Difference between revisions of "Yamaha TZ250"

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{{DISPLAYTITLE:{{PAGENAME}}: history, specs, pictures}}
==The TZ250==
==The TZ250==


At the start of 1972, Yamaha Factory mechanic Ferry Brouwer fitted a pre-production watercooled top end set-up to "Brit" Chas Mortimer's TD3. The paddock was buzzing with excitement at this revelation and by the time the GP season had kicked off, several other leading riders had appeared with the same equipment.
At the start of 1972, [[Yamaha]] Factory mechanic Ferry Brouwer fitted a pre-production [[watercooled]] top end set-up to "Brit" Chas Mortimer's [[Yamaha TD3|TD3]]. The paddock was buzzing with excitement at this revelation and by the time the GP season had kicked off, several other leading riders had appeared with the same equipment.


==TZ250A==
==TZ250A==
[[Image:1973-Yamaha-TZ250A.jpg|right|thumb|1973 Yamaha TZ250A]]
[[Image:1973-Yamaha-TZ250A.jpg|right|thumb|1973 Yamaha TZ250A]]
The TZ250A came out in June 1973 and, like the 350, was virtually unchanged porting wise from the previous aircooled racer apart from a slight widening of the main transfers, also, the exhausts were unchanged.
The '''TZ250A''' came out in June 1973 and, like the 350, was virtually unchanged porting wise from the previous aircooled racer apart from a slight widening of the main transfers, also, the exhausts were unchanged.


Unlike the TZ350, Yamaha chose to have built-in automatically variable ignition advance in it's Hitachi TIA02-16 CDI unit. It was programmed to advance linearly from the initial mark alignment static to a maximum advance of typically 14 degrees at 3000rpm. It then returned slowly and linearly as the revs increased, reaching the original alignment set point again at 10,000 rpm. Beyond 10,000 rpm it continued to
Major differences from the TZ350 included barrels and pistons, cylinder head and primary transmission which also required a different water pump gear.
retard at the same rate at which it approached 10,000 rpm. (i.e. 2 degrees per 1000 rpm)


Yamaha also chose to "beef up" the  main and small-end crank bearings as well as a few other minor mods  . Output was up slightly from the TD3 to 51bhp @ 10,500rpm.
Yamaha also chose to "beef up" the  [[main bearings|main]] and small-end crank bearings as well as a few other minor mods  . Output was up slightly from the TD3 to 51bhp @ 10,500rpm.


==TZ250B==
==TZ250B==
[[Image:Bare-Yamaha-TZ250B.jpg|right|thumb|Bare Yamaha TZ250B]]
[[Image:Bare-Yamaha-TZ250B.jpg|left|thumb|Bare Yamaha TZ250B]]
<br style="clear: left"/>
"The following year's model, the "B" was virtually identical to the "A". ( '74 and '75 must have been very frustrating times for TZ customers ! )
"The following year's model, the "B" was virtually identical to the "A". ( '74 and '75 must have been very frustrating times for TZ customers ! )


==TZ250C==
==TZ250C==
1976 saw the appearance of the much awaited TZ250 C. The biggest news here was the new "Monoshock" chassis, with the rear shock featuring adjustable pre-load and compression damping, as well as disc brakes front and rear. Motor-wise, the factory chose to pursue ease of riding rather than outright horsepower. Revised porting comprising wider intake and transfer ports with altered angles of entry, raised compression and a new exhaust achieved this for them to a certain degree. The exhaust was mounted on new design brackets, and the clutch basket "boss" to primary driven gear attachment was improved by changing from previous model's "dog" teeth to a  female spline, this of course required the primary driven gear to be altered to utilise a male spline. The bike sold remarkably well at just £ 1,500 including a well stocked spares kit.
[[Image:1976-Yamaha-TZ250C-left-bare.jpg|right|thumb|1976 Yamaha TZ250C left bare]]
1976 saw the appearance of the much awaited '''TZ250C'''. The biggest news here was the new "Monoshock" chassis, with the rear shock featuring adjustable pre-load and compression damping, as well as disc brakes front and rear. Motor-wise, the factory chose to pursue ease of riding rather than outright horsepower. Revised porting comprising wider intake and [[transfer port]]s with altered angles of entry, raised compression and a new exhaust achieved this for them to a certain degree. The exhaust was mounted on new design brackets, and the clutch basket "boss" to primary driven gear attachment was improved by changing from previous model's "dog" teeth to a  female spline, this of course required the primary driven gear to be altered to utilise a male spline. The bike sold remarkably well at just £ 1,500 including a well stocked spares kit.
 




==TZ250D==
==TZ250D==
The "D" model of 1977 was just about identical to the previous model except for the inclusion of revised heads with angled spark plugs and new expansion chambers with silencers as standard issue. Minor changes included the side gearbox drain bolt gasket, 2 crank web halves, base gasket and the centre crank bearing.  Carburettor mods including new floats, float chamber gaskets and choke systems also appeared. Peak power hopped up by 1 to 53bhp@ 10,500rpm.
The "D" model of 1977 was just about identical to the previous model except for the inclusion of revised heads with angled spark plugs and new expansion chambers with silencers as standard issue. Minor changes included the side gearbox drain bolt gasket, 2 crank web halves, base gasket and the center crank bearing.  Carburetor mods including new floats, [[float chamber]] gaskets and choke systems also appeared. Peak power hopped up by 1 to 53bhp@ 10,500rpm.
 
==TZ250E==
[[Image:Yamaha-TZ250E.jpg|left|thumb|Yamaha TZ250E]]
[[Image:1978 Yamaha TZ250E.jpg|left|thumb|1978 Yamaha TZ250E]]
 
<br style="clear: left"/>


==TZ250D==
The factory's 1978 250cc offering, the "E" was a little disappointing in that it was virtually unchanged from the previous year's offering, apart from a new chassis which had the engine sitting approx. 20mm further forward, the bike's [[swingarm ]] remained the same. The front of the engine was retained by a pair of alloy mounting plates which required an additional 20 or so bolts, nuts and washers to secure to the engine and frame. The rear lower engine mounting bolt was also lengthened by 5mm.  A TZ250E prepared by [[Kel Carruthers]] and ridden by Californian [[Kenny Roberts]] notched many wins in the 1978 World Championships.
The factory's 1978 250cc offering, the "E" was a little disappointing in that it was virtually unchanged from the previous year's offering, apart from a new chassis which had the engine sitting approx. 20mm further forward, the bike's swingarm remained the same. The front of the engine was retained by a pair of alloy mounting plates which required an additional 20 or so bolts, nuts and washers to secure to the engine and frame. The rear lower engine mounting bolt was also lengthened by 5mm.


==TZ250F==
==TZ250F==
The TZ250 F heralded welcome news for Yamaha fans when it was released in 1979. A 11kg weight reduction was achieved through further changes to the frame, (despite the fact they reverted back to welded steel engine mounting brackets from the alloy ones on the "E") including a steeper rake and an alloy swingarm, as well as this the bike featured a new exhaust and mounting system, an additional o-ring (from the previous single o-ring) in the header pipe, new conrod, wider intake port and minor carburettor mods.  The primary drive gear picked up 2 teeth to match the 350's 25, the cylinder drain tube was altered. A dipstick was also introduced and the brake calipers became cast alloy units like the 750's . Power remained the same as it had since the "D" at 53bhp @ 10,500rpm.  A new fairing adorned the machine which was pointed below the header pipes and eliminated the old aluminium belly pan, a new fuel tank and seat unit appeared, and the clutch cover was reduced in size to a pressed aluminium job (the previous models utilised a cast aluminium unit completely covering the clutch) surrounding just the rear of the clutch unit.
The '''TZ250F''' heralded welcome news for Yamaha fans when it was released in 1979. A 11kg weight reduction was achieved through further changes to the frame, (despite the fact they reverted back to welded steel engine mounting brackets from the alloy ones on the "E") including a steeper rake and an alloy swingarm, as well as this the bike featured a new exhaust and mounting system, an additional o-ring (from the previous single o-ring) in the header pipe, new conrod, wider intake port and minor carburetor mods.  The primary drive gear picked up 2 teeth to match the 350's 25, the cylinder drain tube was altered. A dipstick was also introduced and the brake [[caliper]]s became cast alloy units like the 750's . Power remained the same as it had since the "D" at 53bhp @ 10,500rpm.  A new fairing adorned the machine which was pointed below the header pipes and eliminated the old aluminum belly pan, a new fuel tank and seat unit appeared, and the clutch cover was reduced in size to a pressed aluminum job (the previous models utilised a cast aluminum unit completely covering the clutch) surrounding just the rear of the clutch unit.


==TZ250G==
==TZ250G==
1980's "G" model was a further departure from the "norm" of the past 3 or 4 years. New, larger diameter forks were fitted in an effort to combat the front end "patter" problem that was frustrating so many riders. Motor-wise Yamaha went all-out for peak horsepower at the expense of engine lifespan by drastically increasing the inlet timing period by removing almost 8mm from the rear of the pistons (and slightly increasing bore size) . This mod caused real problems with piston wear, despite the factory's attempt to counteract it with the inclusion of a short supporting "tongue" protruding down from the top of the inlet port in a vain attempt to reduce piston rocking. TZ250 G's were, as a result, very expensive to maintain, requiring re-builds after every race, though no-one complained about the extra 4bhp it provided over the D/E/F models ! Yamaha also increased the width of the secondary transfers slightly this year as well as fitting powerjet carburettors.
[[Image:Yamaha-TZ250G.jpg|right|thumb|Yamaha TZ250G]]
[[Image:1980 Yamaha TZ250G.jpg|left|thumb|1980 Yamaha TZ250G]]
 
 
1980's "G" model was a further departure from the "norm" of the past 3 or 4 years. But they were still just incremental type changes since Yamaha had virtually monopolized this class of racing in 1979.  New, larger diameter forks were fitted in an effort to combat the front end "patter" problem that was frustrating so many riders. Motor-wise Yamaha went all-out for peak horsepower at the expense of engine lifespan by drastically increasing the inlet timing period by removing almost 8mm from the rear of the pistons (and slightly increasing bore size) . Thie allowed for 500 rpm higher revlimit.  This mod caused real problems with piston wear, despite the factory's attempt to counteract it with the inclusion of a short supporting "tongue" protruding down from the top of the inlet port in a vain attempt to reduce piston rocking. TZ250 G's were, as a result, very expensive to maintain, requiring re-builds after every race, though no-one complained about the extra 4bhp it provided over the D/E/F models ! Yamaha also increased the width of the secondary transfers slightly this year as well as fitting powerjet carburetors.
 
{{clear}}


==TZ250H==
==TZ250H==
[[Image:Yamaha-TZ250H.jpg|right|thumb|Yamaha TZ250H]]
The 1981  "H" represented the factory's first departure from the popular 54mm bore x 54mm stroke (essentially) configuration of the previous 9 years along with a switch to an  individual cylinder casting configuration. In an effort to further boost horsepower, the bore was increased to 56mm and stroke reduced to 50.7mm, achieving the full 249cc in the process and mechanical exhaust power valves were fitted, as was a transmission oil pump to deliver the reduced oil capacity of the gearbox to crucial points. The "H" had a 38mm shorter motor than the "G" and 36mm ZC series Mikuni carbs replaced the usual 34mm SC's, which had been in use on the 250's since the TD3 way back in 1972. Intake port was again widened, as were the secondary transfers for the second year running.
The 1981  "H" represented the factory's first departure from the popular 54mm bore x 54mm stroke (essentially) configuration of the previous 9 years along with a switch to an  individual cylinder casting configuration. In an effort to further boost horsepower, the bore was increased to 56mm and stroke reduced to 50.7mm, achieving the full 249cc in the process and mechanical exhaust power valves were fitted, as was a transmission oil pump to deliver the reduced oil capacity of the gearbox to crucial points. The "H" had a 38mm shorter motor than the "G" and 36mm ZC series Mikuni carbs replaced the usual 34mm SC's, which had been in use on the 250's since the TD3 way back in 1972. Intake port was again widened, as were the secondary transfers for the second year running.


The motor spun in reverse direction as the factory tried to further reduce the stress on the rear of the pistons. The crank was no longer a single unit, it was now a pair of cranks with a gear on the end to deliver the power to the gearbox. Despite the frame shedding 3kg, the overall weight was reduced by just 1kg. The steering rake was  altered and the swingarm  also lengthened to compensate for the shorter frame length of this model. The engine was now mounted slightly further towards the front of the bike. The new rear shock became fully adjustable for both compression and rebound damping as well as pre-load and the shock picked up a rear rubber mounting. The fork diameter went up by 1mm and brake wise the factory reverted back to the old cast iron calipers which didn't bend under pressure and also didn't fade when hot. The new ignition dropped an igniter and pulser coil, there was now just one of each and the  inner clutch hub now became a single piece unit to eliminate one reliability problem from previous years. The un-necessary neutral switch mounting disappeared
Unlike the [[Yamaha TZ350|TZ350]], and earlier Yamaha TZ250, which shared many components including ignition, Yamaha chose to have built-in automatically variable ignition advance in it's Hitachi TIA02-16 CDI unit. It was programmed to advance linearly from the initial mark alignment static to a maximum advance of typically 14 degrees at 3000rpm. It then returned slowly and linearly as the revs increased, reaching the original alignment set point again at 10,000 rpm. Beyond 10,000 rpm it continued to retard at the same rate at which it approached 10,000 rpm. (i.e. 2 degrees per 1000 rpm).
 
The motor spun in reverse direction as the factory tried to further reduce the stress on the rear of the pistons. The crank was no longer a single unit, it was now a pair of cranks with a gear on the end to deliver the power to the gearbox. Despite the frame shedding 3kg, the overall weight was reduced by just 1kg. The steering rake was  altered and the swingarm  also lengthened to compensate for the shorter frame length of this model. The engine was now mounted slightly further towards the front of the bike. The new rear shock became fully adjustable for both compression and rebound damping as well as pre-load and the shock picked up a rear rubber mounting. The fork diameter went up by 1mm and brake wise the factory reverted back to the old cast iron [[caliper]]s which didn't bend under pressure and also didn't [[brake fade|fade]] when hot. The new ignition dropped an igniter and pulser coil, there was now just one of each and the  inner clutch hub now became a single piece unit to eliminate one reliability problem from previous years. The un-necessary neutral switch mounting disappeared


==TZ250J==
==TZ250J==
The "J" of 1982 was virtually identical to the previous model apart from a few minor "glitches" being sorted out from the "H".
The "J" of 1982 was virtually identical to the previous model apart from a few minor "glitches" being sorted out from the "H".
[[Image:Yamaha-TZ250J.jpg|left|thumb|Yamaha TZ250J]]
<br style="clear: left"/>
==TZ250T==
The "T" of 1987.
[[Image:1987-Yamaha-TZ250T-White-5648-0.jpg|left|thumb|1987 Yamaha TZ250T in White]]
[[Image:1987-Yamaha-TZ250T-White-5648-1.jpg|left|thumb|1987 Yamaha TZ250T in White]]
[[Image:1987-Yamaha-TZ250T-White-5648-2.jpg|left|thumb|1987 Yamaha TZ250T in White]]
[[Image:1987-Yamaha-TZ250T-White-5648-3.jpg|left|thumb|1987 Yamaha TZ250T in White]]
[[Image:1987-Yamaha-TZ250T-White-5648-4.jpg|left|thumb|1987 Yamaha TZ250T in White]]
<br style="clear: left"/>
==TZ250A==
[[Image:1990 Yamaha TZ250A.jpg|right|thumb|1990 Yamaha TZ250A]]
Marboro Team Roberts machine ridden to second place in the Unlimited Class of Formula USA by Rich Oliver.  The "A" model was the last model to use the [[parallel twin]] motor design.  The following year the [[motor]] was completely re-designed in a [[v-twin]] configuration.
==1992 TZ250D==
[[Image:1992 Yamaha TZ250D.jpg|left|thumb|1992 Yamaha TZ250D]]
Colin Edwards rode this [[Yamaha]] to win the American Motorcycle Association Road Racing 250cc Championship in 1992. This model has a [[v-twin]] engine design, a departure from the traditional parallel twin motors that had been used since the mid 1960s. The V-twin is narrower, and has less vibration, so the chassis can be made smaller and lighter. Another bonus is that the design gives more freedom to cylinder port design.
{{clear}}
==1998 TZ250 4TW==
<gallery mode='packed-hover'>
File:1998-yamaha-tz250-4tw-0.jpg|1998 Yamaha TZ250 4TW
File:1998-yamaha-tz250-4tw-1.jpg|1998 Yamaha TZ250 4TW
File:1998-yamaha-tz250-4tw-2.jpg|1998 Yamaha TZ250 4TW
File:1998-yamaha-tz250-4tw-3.jpg|1998 Yamaha TZ250 4TW
File:1998-yamaha-tz250-4tw-4.jpg|1998 Yamaha TZ250 4TW
</gallery>
==TZ250K==
<gallery mode='packed-hover'>
File:2001-Yamaha-TZ250K1-Silver-8116-0.jpg|left|thumb|2001 Yamaha TZ250K1 in Silver
File:2001-Yamaha-TZ250K1-Silver-8116-1.jpg|left|thumb|2001 Yamaha TZ250K1 in Silver
File:2001-Yamaha-TZ250K1-Silver-8116-2.jpg|left|thumb|2001 Yamaha TZ250K1 in Silver
File:2001-Yamaha-TZ250K1-Silver-8116-3.jpg|left|thumb|2001 Yamaha TZ250K1 in Silver
File:2001-Yamaha-TZ250K1-Silver-8116-4.jpg|left|thumb|2001 Yamaha TZ250K1 in Silver
File:2001-Yamaha-TZ250K1-Silver-8116-5.jpg|left|thumb|2001 Yamaha TZ250K1 in Silver
File:2001-Yamaha-TZ250K1-Silver-8116-6.jpg|left|thumb|2001 Yamaha TZ250K1 in Silver
File:2001-Yamaha-TZ250K1-Silver-8116-7.jpg|left|thumb|2001 Yamaha TZ250K1 in Silver
</gallery>
<br style="clear: left"/>
==2002==
[[Image:2002 Yamaha TZ250.jpg|right|thumb|2002 Yamaha TZ250]]
With the ban on [[two cycle]] [[motors]] for street use, the [[American Motorcycle Association]] decided to discontinued the 250cc road racing class at the end of 2004.  Californian Rich Oliver proceeded to win every 250cc race in the final year on this machine, including the very last 250 AMA race which took place at [[Barber Motorsports Park]].
{{clear}}
==TZ250 Specifications==
<table>
  <tr >
    <td  >
    TZ 250</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
    <td  >&nbsp;</td>
  </tr>
  <tr  >
    <td  >
    Specifications</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
  </tr>
  <tr  >
    <td  >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
  </tr>
  <tr  >
    <td  >
    MODEL</td>
    <td >&nbsp;</td>
    <td >
    &nbsp; TZ 250 A</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;TZ 250 B</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp; TZ250 C</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp; TZ250 D</td>
    <td >&nbsp;</td>
    <td >
    &nbsp; TZ 250 E</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp; TZ250 F</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;TZ 250 G</td>
    <td >&nbsp;</td>
    <td >
    &nbsp; TZ 250 H</td>
    <td >&nbsp;</td>
    <td >
    &nbsp; TZ 250 J</td>
  </tr>
  <tr  >
    <td  >
    </td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
  </tr>
  <tr  >
    <td  >
    Year</td>
    <td >&nbsp;</td>
    <td align="right" >
    1973</td>
    <td >&nbsp;</td>
    <td align="right" >
    1974</td>
    <td >&nbsp;</td>
    <td align="right" >
    1976</td>
    <td >&nbsp;</td>
    <td align="right" >
    1977</td>
    <td >&nbsp;</td>
    <td align="right" >
    1978</td>
    <td >&nbsp;</td>
    <td align="right" >
    1979</td>
    <td >&nbsp;</td>
    <td align="right" >
    1980</td>
    <td >&nbsp;</td>
    <td align="right" >
    1981</td>
    <td >&nbsp;</td>
    <td align="right" >
    1982</td>
  </tr>
  <tr  >
    <td  >
    Model Code from</td>
    <td >&nbsp;</td>
    <td >
    DS7/ 430-991101</td>
    <td >&nbsp;</td>
    <td >
    DS7/ 430-991471</td>
    <td >&nbsp;</td>
    <td >
    DS7/ 430-993101</td>
    <td >&nbsp;</td>
    <td >
    DS7/ 430-994101</td>
    <td >&nbsp;</td>
    <td >
    DS7/ 430-995101</td>
    <td >&nbsp;</td>
    <td >
    DS7/ 430-997101</td>
    <td >&nbsp;</td>
    <td >
    4A1/ 000101</td>
    <td >&nbsp;</td>
    <td >
    5F7/ 000101</td>
    <td >&nbsp;</td>
    <td >&nbsp;</td>
  </tr>
  <tr  >
    <td  >
    Bore (mm)</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54.25</td>
    <td >&nbsp;</td>
    <td align="right" >
    56</td>
    <td >&nbsp;</td>
    <td align="right" >
    56</td>
  </tr>
  <tr  >
    <td  >
    Stroke (mm)</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    54</td>
    <td >&nbsp;</td>
    <td align="right" >
    50.7</td>
    <td >&nbsp;</td>
    <td align="right" >
    50.7</td>
  </tr>
  <tr  >
    <td  >
    Capacity (cc)</td>
    <td >&nbsp;</td>
    <td align="right" >
    247</td>
    <td >&nbsp;</td>
    <td align="right" >
    247</td>
    <td >&nbsp;</td>
    <td align="right" >
    247</td>
    <td >&nbsp;</td>
    <td align="right" >
    247</td>
    <td >&nbsp;</td>
    <td align="right" >
    247</td>
    <td >&nbsp;</td>
    <td align="right" >
    247</td>
    <td >&nbsp;</td>
    <td align="right" >
    249</td>
    <td >&nbsp;</td>
    <td align="right" >
    249</td>
    <td >&nbsp;</td>
    <td align="right" >
    249</td>
  </tr>
  <tr  >
    <td  >
    Compression ratio</td>
    <td >&nbsp;</td>
    <td align="right" >
    7.6</td>
    <td >&nbsp;</td>
    <td align="right" >
    7.6</td>
    <td >&nbsp;</td>
    <td align="right" >
    7.85</td>
    <td >&nbsp;</td>
    <td align="right" >
    7.8</td>
    <td >&nbsp;</td>
    <td align="right" >
    7.8</td>
    <td >&nbsp;</td>
    <td align="right" >
    7.8</td>
    <td >&nbsp;</td>
    <td align="right" >
    7.6</td>
    <td >&nbsp;</td>
    <td align="right" >
    7.6</td>
    <td >&nbsp;</td>
    <td align="right" >
    7.6</td>
  </tr>
  <tr  >
    <td  >
    bhp</td>
    <td >&nbsp;</td>
    <td align="right" >
    51</td>
    <td >&nbsp;</td>
    <td align="right" >
    51</td>
    <td >&nbsp;</td>
    <td align="right" >
    52</td>
    <td >&nbsp;</td>
    <td align="right" >
    53</td>
    <td >&nbsp;</td>
    <td align="right" >
    53</td>
    <td >&nbsp;</td>
    <td align="right" >
    53</td>
    <td >&nbsp;</td>
    <td align="right" >
    55</td>
    <td >&nbsp;</td>
    <td align="right" >
    57</td>
    <td >&nbsp;</td>
    <td align="right" >
    57</td>
  </tr>
  <tr  >
    <td  >
    &nbsp;&nbsp; @ rpm</td>
    <td >&nbsp;</td>
    <td  >
    10,500</td>
    <td >&nbsp;</td>
    <td  >
    10,500</td>
    <td >&nbsp;</td>
    <td  >
    10,500</td>
    <td >&nbsp;</td>
    <td  >
    10,500</td>
    <td >&nbsp;</td>
    <td  >
    10,500</td>
    <td >&nbsp;</td>
    <td  >
    10,500</td>
    <td >&nbsp;</td>
    <td >
    11,500</td>
    <td >&nbsp;</td>
    <td >
    11,000</td>
    <td >&nbsp;</td>
    <td >
    11,000</td>
  </tr>
  <tr  >
    <td  >
    Ignition type</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CDI</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CDI</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CDI</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CDI</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CDI</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CDI</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CDI</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CDI</td>
    <td >&nbsp;</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CDI</td>
  </tr>
  <tr  >
    <td  >
    Timing (mm btdc)</td>
    <td >&nbsp;</td>
    <td align="right" >
    2</td>
    <td >&nbsp;</td>
    <td align="right" >
    2</td>
    <td >&nbsp;</td>
    <td align="right" >
    2</td>
    <td >&nbsp;</td>
    <td align="right" >
    2</td>
    <td >&nbsp;</td>
    <td align="right" >
    2</td>
    <td >&nbsp;</td>
    <td align="right" >
    2</td>
    <td >&nbsp;</td>
    <td align="right" >
    2</td>
    <td >&nbsp;</td>
    <td align="right" >
    2</td>
    <td >&nbsp;</td>
    <td align="right" >
    2</td>
  </tr>
  <tr  >
    <td  >
    Carburettor</td>
    <td >&nbsp;</td>
    <td colspan="2" >
    &nbsp;&nbsp;&nbsp; Mikuni VM34SC</td>
    <td colspan="2" >
    &nbsp;&nbsp;&nbsp; Mikuni VM34SC</td>
    <td colspan="2" >
    &nbsp;&nbsp;&nbsp; Mikuni VM34SC</td>
    <td colspan="2" >
    &nbsp;&nbsp;&nbsp; Mikuni VM34SC</td>
    <td colspan="2" >
    &nbsp;&nbsp;&nbsp; Mikuni VM34SC</td>
    <td colspan="2" >
    &nbsp;&nbsp;&nbsp; Mikuni VM34SC</td>
    <td colspan="2" >
    &nbsp;&nbsp;&nbsp; Mikuni VM34SC</td>
    <td >
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Mikuni VM36</td>
    <td >&nbsp;</td>
    <td >
    Mikuni VM36</td>
  </tr>
  <tr  >
    <td  >
    Primary Drive</td>
    <td >&nbsp;</td>
    <td align="right" >
    3.35</td>
    <td >&nbsp;</td>
    <td align="right" >
    3.35</td>
    <td >&nbsp;</td>
    <td align="right" >
    3.35</td>
    <td >&nbsp;</td>
    <td align="right" >
    3.35</td>
    <td >&nbsp;</td>
    <td align="right" >
    3.35</td>
    <td >&nbsp;</td>
    <td align="right" >
    3.35</td>
    <td >&nbsp;</td>
    <td align="right" >
    3.35</td>
    <td >&nbsp;</td>
    <td align="right" >
    3.15</td>
    <td >&nbsp;</td>
    <td align="right" >
    3.15</td>
  </tr>
  <tr  >
    <td  >
    Final Drive</td>
    <td >&nbsp;</td>
    <td >
    34 / 16</td>
    <td >&nbsp;</td>
    <td >
    34 / 16</td>
    <td >&nbsp;</td>
    <td >
    34 / 16</td>
    <td >&nbsp;</td>
    <td >
    34 / 16</td>
    <td >&nbsp;</td>
    <td >
    34 / 16</td>
    <td >&nbsp;</td>
    <td >
    34 / 16</td>
    <td >&nbsp;</td>
    <td >
    34 / 16</td>
    <td >&nbsp;</td>
    <td >
    35 / 17</td>
    <td >&nbsp;</td>
    <td >
    35 / 17</td>
  </tr>
  <tr  >
    <td  >
    6th gear ratio</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.81</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.81</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.81</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.81</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.81</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.81</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.81</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.91</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.91</td>
  </tr>
  <tr  >
    <td  >
    5th gear ratio</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.87</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.87</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.87</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.87</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.87</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.87</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.87</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.96</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.96</td>
  </tr>
  <tr  >
    <td  >
    4th gear ratio</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.96</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.96</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.96</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.96</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.96</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.96</td>
    <td >&nbsp;</td>
    <td align="right" >
    0.96</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.08</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.08</td>
  </tr>
  <tr  >
    <td  >
    3rd gear ratio</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.13</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.13</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.13</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.13</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.13</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.13</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.13</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.26</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.26</td>
  </tr>
  <tr  >
    <td  >
    2nd gear ratio</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.42</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.42</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.42</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.42</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.42</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.42</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.42</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.56</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.56</td>
  </tr>
  <tr  >
    <td  >
    1st gear ratio</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.93</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.93</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.93</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.93</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.93</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.93</td>
    <td >&nbsp;</td>
    <td align="right" >
    1.93</td>
    <td >&nbsp;</td>
    <td align="right" >
    2.07</td>
    <td >&nbsp;</td>
    <td align="right" >
    2.07</td>
  </tr>
  <tr  >
    <td  >
    Over-all top gear ratio</td>
    <td >&nbsp;</td>
    <td align="right" >
    5.78</td>
    <td >&nbsp;</td>
    <td align="right" >
    5.78</td>
    <td >&nbsp;</td>
    <td align="right" >
    5.78</td>
    <td >&nbsp;</td>
    <td align="right" >
    5.78</td>
    <td >&nbsp;</td>
    <td align="right" >
    5.78</td>
    <td >&nbsp;</td>
    <td align="right" >
    5.78</td>
    <td >&nbsp;</td>
    <td align="right" >
    5.78</td>
    <td >&nbsp;</td>
    <td align="right" >
    5.92</td>
    <td >&nbsp;</td>
    <td align="right" >
    5.92</td>
  </tr>
  <tr  >
    <td  >
    Fuel capacity</td>
    <td >&nbsp;</td>
    <td align="right" >
    23</td>
    <td >&nbsp;</td>
    <td align="right" >
    23</td>
    <td >&nbsp;</td>
    <td align="right" >
    23</td>
    <td >&nbsp;</td>
    <td align="right" >
    23</td>
    <td >&nbsp;</td>
    <td align="right" >
    23</td>
    <td >&nbsp;</td>
    <td align="right" >
    23</td>
    <td >&nbsp;</td>
    <td align="right" >
    23</td>
    <td >&nbsp;</td>
    <td align="right" >
    23.5</td>
    <td >&nbsp;</td>
    <td align="right" >
    23.5</td>
  </tr>
  <tr  >
    <td  >
    Gearbox oil capacity</td>
    <td >&nbsp;</td>
    <td >
    1,700 cc</td>
    <td >&nbsp;</td>
    <td >
    1,700 cc</td>
    <td >&nbsp;</td>
    <td >
    1,700 cc</td>
    <td >&nbsp;</td>
    <td >
    1,700 cc</td>
    <td >&nbsp;</td>
    <td >
    1,700 cc</td>
    <td >&nbsp;</td>
    <td >
    1,700 cc</td>
    <td >&nbsp;</td>
    <td >
    1,700 cc</td>
    <td >&nbsp;</td>
    <td >
    900cc</td>
    <td >&nbsp;</td>
    <td >
    900cc</td>
  </tr>
  <tr  >
    <td  >
    Front tyre</td>
    <td >&nbsp;</td>
    <td >
    2.75&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    2.75&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    2.75&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    2.75&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    2.75&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    2.75&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.0&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.0&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.0&quot; x 18&quot;</td>
  </tr>
  <tr  >
    <td  >
    Rear tyre</td>
    <td >&nbsp;</td>
    <td >
    3.0&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.0&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.0&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.0&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.0&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.0&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.5&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.75&quot; x 18&quot;</td>
    <td >&nbsp;</td>
    <td >
    3.75&quot; x 18&quot;</td>
  </tr>
  <tr  >
    <td  >
    Front brake</td>
    <td >&nbsp;</td>
    <td >
    2 x Twin L-Shoe</td>
    <td >&nbsp;</td>
    <td >
    2 x Twin L-Shoe</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
  </tr>
  <tr  >
    <td  >
    Rear brake</td>
    <td >&nbsp;</td>
    <td colspan="2" >
    1 x Single L-Shoe</td>
    <td colspan="2" >
    1 x Single L-Shoe</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
    <td >&nbsp;</td>
    <td >
    Disc</td>
  </tr>
  <tr  >
    <td  >
    Rear suspension</td>
    <td >&nbsp;</td>
    <td >
    Twin Shock</td>
    <td >&nbsp;</td>
    <td >
    Twin Shock</td>
    <td >&nbsp;</td>
    <td >
    Mono-shock</td>
    <td >&nbsp;</td>
    <td >
    Mono-shock</td>
    <td >&nbsp;</td>
    <td >
    Mono-shock</td>
    <td >&nbsp;</td>
    <td >
    Mono-shock</td>
    <td >&nbsp;</td>
    <td >
    Mono-shock</td>
    <td >&nbsp;</td>
    <td >
    Mono-shock</td>
    <td >&nbsp;</td>
    <td >
    Mono-shock</td>
  </tr>
  <tr  >
    <td  >
    Wheelbase (mm)</td>
    <td >&nbsp;</td>
    <td >
    1,300</td>
    <td >&nbsp;</td>
    <td  >
    1,300</td>
    <td >&nbsp;</td>
    <td >
    1,315</td>
    <td >&nbsp;</td>
    <td >
    1,315</td>
    <td >&nbsp;</td>
    <td >
    1,315</td>
    <td >&nbsp;</td>
    <td >
    1,320</td>
    <td >&nbsp;</td>
    <td>
    1,320</td>
    <td >&nbsp;</td>
    <td >
    1,320</td>
    <td >&nbsp;</td>
    <td >
    1,320</td>
  </tr>
  <tr  >
    <td  >
    Width (mm)</td>
    <td >&nbsp;</td>
    <td align="right" >
    510</td>
    <td >&nbsp;</td>
    <td align="right" >
    510</td>
    <td >&nbsp;</td>
    <td align="right" >
    630</td>
    <td >&nbsp;</td>
    <td align="right" >
    630</td>
    <td >&nbsp;</td>
    <td align="right" >
    630</td>
    <td >&nbsp;</td>
    <td align="right" >
    630</td>
    <td >&nbsp;</td>
    <td align="right" >
    630</td>
    <td >&nbsp;</td>
    <td align="right" >
    615</td>
    <td >&nbsp;</td>
    <td align="right" >
    615</td>
  </tr>
  <tr  >
    <td  >
    Length (mm)</td>
    <td >&nbsp;</td>
    <td >
    1,940</td>
    <td >&nbsp;</td>
    <td>
    1,940</td>
    <td >&nbsp;</td>
    <td>
    1,930</td>
    <td >&nbsp;</td>
    <td>
    1,930</td>
    <td >&nbsp;</td>
    <td>
    1,930</td>
    <td >&nbsp;</td>
    <td>
    1,935</td>
    <td >&nbsp;</td>
    <td>
    1,935</td>
    <td >&nbsp;</td>
    <td>
    1,950</td>
    <td >&nbsp;</td>
    <td>
    1,950</td>
  </tr>
  <tr  >
    <td  >
    Rake (degrees)</td>
    <td >&nbsp;</td>
    <td align="right" >
    27.5</td>
    <td >&nbsp;</td>
    <td align="right" >
    27.5</td>
    <td >&nbsp;</td>
    <td align="right" >
    27.5</td>
    <td >&nbsp;</td>
    <td align="right" >
    27.5</td>
    <td >&nbsp;</td>
    <td align="right" >
    27.5</td>
    <td >&nbsp;</td>
    <td align="right" >
    26</td>
    <td >&nbsp;</td>
    <td align="right" >
    26</td>
    <td >&nbsp;</td>
    <td align="right" >
    24.5</td>
    <td >&nbsp;</td>
    <td align="right" >
    24.5</td>
  </tr>
  <tr  >
    <td  >
    Trail (mm)</td>
    <td >&nbsp;</td>
    <td align="right" >
    90</td>
    <td >&nbsp;</td>
    <td align="right" >
    90</td>
    <td >&nbsp;</td>
    <td align="right" >
    74</td>
    <td >&nbsp;</td>
    <td align="right" >
    74</td>
    <td >&nbsp;</td>
    <td align="right" >
    74</td>
    <td >&nbsp;</td>
    <td align="right" >
    97</td>
    <td >&nbsp;</td>
    <td align="right" >
    92</td>
    <td >&nbsp;</td>
    <td align="right" >
    87</td>
    <td >&nbsp;</td>
    <td align="right" >
    87</td>
  </tr>
  <tr  >
    <td  >
    Dry weight</td>
    <td >&nbsp;</td>
    <td align="right" >
    110</td>
    <td >&nbsp;</td>
    <td align="right" >
    110</td>
    <td >&nbsp;</td>
    <td align="right" >
    118</td>
    <td >&nbsp;</td>
    <td align="right" >
    118</td>
    <td >&nbsp;</td>
    <td align="right" >
    118</td>
    <td >&nbsp;</td>
    <td align="right" >
    107</td>
    <td >&nbsp;</td>
    <td align="right" >
    107</td>
    <td >&nbsp;</td>
    <td align="right" >
    106</td>
    <td >&nbsp;</td>
    <td align="right" >
    106</td>
  </tr>
</table>


==External Links==
==External Links==
*[http://groups.yahoo.com/group/TZHEADS TZHeads at Yahoo Groups]
*[http://groups.yahoo.com/group/TZHEADS TZHeads at Yahoo Groups]
{{Yamaha}}


[[Category:Yamaha motorcycles|TZ250]]
[[Category:Yamaha TZ series]]


[[Category:Yamaha motorcycles|TZ250]]
{{Motorcycle
|name            = '''Yamaha TZ250'''
|image            =
|aka              = TZ 250
|manufacturer    = [[Yamaha]]
|parent_company  =
|production      = 2002
|model_year      =
|predecessor      =
|successor        =
|class            = [[Racing]]
|engine          = v2, two-stroke
|bore_stroke      = 56.0mm x 50.7mm
|compression      =
|top_speed        =
|power            = 85.02 HP (63.4 KW) @ 12250RPM
|torque          = 36.88 ft/lbs (50.0 Nm) @ 11750RPM
|fuel_system      =
|ignition        =
|spark_plug      =
|battery          = 8.2:1
|transmission    =
|frame            =
|suspension      =
|brakes          =Front: dual disc <br>Rear: single disc
|front_tire      = {{tire|120/60-r17}}
|rear_tire    = {{tire|165/55-r17}}
|rake_trail      =
|wheelbase        = 52.95 inches (1345 mm)
|length          = 77.05 inches (1957 mm)
|width            = 25.59 inches (650 mm)
|height          = 42.4 inches (1077 mm)
|seat_height      = 30.43 inches (773 mm)
|dry_weight      = 229.28 pounds (104.0 Kg)
|wet_weight      =
|fuel_capacity    =
|oil_capacity    =
|fuel_consumption =
|turning_radius  =
|related          =
|competition      =
}}
 
The '''[[Yamaha]] TZ250''' was a v2, two-stroke Racing [[motorcycle]] produced by [[Yamaha]] in 2002. Max [[torque]] was 36.88 ft/lbs (50.0 Nm) @ 11750 RPM. Claimed [[horsepower]] was 85.02 HP (63.4 KW) @ 12250 RPM. 
 
==Engine==
The engine was a [[liquid cooled]] v2, two-stroke. A 56.0mm [[bore]] x 50.7mm [[stroke]] result in a [[displacement]] of just 249.0 cubic centimeters. 
 
==Chassis==
It came with a 120/60-r17 front [[tire]] and a 165/55-r17 rear tire. Stopping was achieved via dual disc in the front and a single disc in the rear. The bike weighed just 229.28 pounds (104.0 Kg). The wheelbase was 52.95 inches (1345 mm) long. 
 
==In Media==
* [https://motopixel.org/pixel/confessions-of-a-sociopathic-social-climber#yamaha-tz250 Confessions of a Sociopathic Social Climber]
* [https://motopixel.org/pixel/dan-cheng-lu#yamaha-tz250 Dan cheng lu]
* [https://motopixel.org/pixel/i-kondra#yamaha-tz250 I kondra]
 
[[Category:Racing motorcycles]]
[[Category:Yamaha motorcycles]]
[[Category:2000s motorcycles]]
[[Category:Motorcycles needing images]]

Revision as of 04:04, 26 August 2019

The TZ250

At the start of 1972, Yamaha Factory mechanic Ferry Brouwer fitted a pre-production watercooled top end set-up to "Brit" Chas Mortimer's TD3. The paddock was buzzing with excitement at this revelation and by the time the GP season had kicked off, several other leading riders had appeared with the same equipment.

TZ250A

1973 Yamaha TZ250A

The TZ250A came out in June 1973 and, like the 350, was virtually unchanged porting wise from the previous aircooled racer apart from a slight widening of the main transfers, also, the exhausts were unchanged.

Major differences from the TZ350 included barrels and pistons, cylinder head and primary transmission which also required a different water pump gear.

Yamaha also chose to "beef up" the main and small-end crank bearings as well as a few other minor mods . Output was up slightly from the TD3 to 51bhp @ 10,500rpm.

TZ250B

Bare Yamaha TZ250B


"The following year's model, the "B" was virtually identical to the "A". ( '74 and '75 must have been very frustrating times for TZ customers ! )

TZ250C

1976 Yamaha TZ250C left bare

1976 saw the appearance of the much awaited TZ250C. The biggest news here was the new "Monoshock" chassis, with the rear shock featuring adjustable pre-load and compression damping, as well as disc brakes front and rear. Motor-wise, the factory chose to pursue ease of riding rather than outright horsepower. Revised porting comprising wider intake and transfer ports with altered angles of entry, raised compression and a new exhaust achieved this for them to a certain degree. The exhaust was mounted on new design brackets, and the clutch basket "boss" to primary driven gear attachment was improved by changing from previous model's "dog" teeth to a female spline, this of course required the primary driven gear to be altered to utilise a male spline. The bike sold remarkably well at just £ 1,500 including a well stocked spares kit.


TZ250D

The "D" model of 1977 was just about identical to the previous model except for the inclusion of revised heads with angled spark plugs and new expansion chambers with silencers as standard issue. Minor changes included the side gearbox drain bolt gasket, 2 crank web halves, base gasket and the center crank bearing. Carburetor mods including new floats, float chamber gaskets and choke systems also appeared. Peak power hopped up by 1 to 53bhp@ 10,500rpm.

TZ250E

Yamaha TZ250E
1978 Yamaha TZ250E


The factory's 1978 250cc offering, the "E" was a little disappointing in that it was virtually unchanged from the previous year's offering, apart from a new chassis which had the engine sitting approx. 20mm further forward, the bike's swingarm remained the same. The front of the engine was retained by a pair of alloy mounting plates which required an additional 20 or so bolts, nuts and washers to secure to the engine and frame. The rear lower engine mounting bolt was also lengthened by 5mm. A TZ250E prepared by Kel Carruthers and ridden by Californian Kenny Roberts notched many wins in the 1978 World Championships.

TZ250F

The TZ250F heralded welcome news for Yamaha fans when it was released in 1979. A 11kg weight reduction was achieved through further changes to the frame, (despite the fact they reverted back to welded steel engine mounting brackets from the alloy ones on the "E") including a steeper rake and an alloy swingarm, as well as this the bike featured a new exhaust and mounting system, an additional o-ring (from the previous single o-ring) in the header pipe, new conrod, wider intake port and minor carburetor mods. The primary drive gear picked up 2 teeth to match the 350's 25, the cylinder drain tube was altered. A dipstick was also introduced and the brake calipers became cast alloy units like the 750's . Power remained the same as it had since the "D" at 53bhp @ 10,500rpm. A new fairing adorned the machine which was pointed below the header pipes and eliminated the old aluminum belly pan, a new fuel tank and seat unit appeared, and the clutch cover was reduced in size to a pressed aluminum job (the previous models utilised a cast aluminum unit completely covering the clutch) surrounding just the rear of the clutch unit.

TZ250G

Yamaha TZ250G
1980 Yamaha TZ250G


1980's "G" model was a further departure from the "norm" of the past 3 or 4 years. But they were still just incremental type changes since Yamaha had virtually monopolized this class of racing in 1979. New, larger diameter forks were fitted in an effort to combat the front end "patter" problem that was frustrating so many riders. Motor-wise Yamaha went all-out for peak horsepower at the expense of engine lifespan by drastically increasing the inlet timing period by removing almost 8mm from the rear of the pistons (and slightly increasing bore size) . Thie allowed for 500 rpm higher revlimit. This mod caused real problems with piston wear, despite the factory's attempt to counteract it with the inclusion of a short supporting "tongue" protruding down from the top of the inlet port in a vain attempt to reduce piston rocking. TZ250 G's were, as a result, very expensive to maintain, requiring re-builds after every race, though no-one complained about the extra 4bhp it provided over the D/E/F models ! Yamaha also increased the width of the secondary transfers slightly this year as well as fitting powerjet carburetors.

TZ250H

Yamaha TZ250H

The 1981 "H" represented the factory's first departure from the popular 54mm bore x 54mm stroke (essentially) configuration of the previous 9 years along with a switch to an individual cylinder casting configuration. In an effort to further boost horsepower, the bore was increased to 56mm and stroke reduced to 50.7mm, achieving the full 249cc in the process and mechanical exhaust power valves were fitted, as was a transmission oil pump to deliver the reduced oil capacity of the gearbox to crucial points. The "H" had a 38mm shorter motor than the "G" and 36mm ZC series Mikuni carbs replaced the usual 34mm SC's, which had been in use on the 250's since the TD3 way back in 1972. Intake port was again widened, as were the secondary transfers for the second year running.

Unlike the TZ350, and earlier Yamaha TZ250, which shared many components including ignition, Yamaha chose to have built-in automatically variable ignition advance in it's Hitachi TIA02-16 CDI unit. It was programmed to advance linearly from the initial mark alignment static to a maximum advance of typically 14 degrees at 3000rpm. It then returned slowly and linearly as the revs increased, reaching the original alignment set point again at 10,000 rpm. Beyond 10,000 rpm it continued to retard at the same rate at which it approached 10,000 rpm. (i.e. 2 degrees per 1000 rpm).

The motor spun in reverse direction as the factory tried to further reduce the stress on the rear of the pistons. The crank was no longer a single unit, it was now a pair of cranks with a gear on the end to deliver the power to the gearbox. Despite the frame shedding 3kg, the overall weight was reduced by just 1kg. The steering rake was altered and the swingarm also lengthened to compensate for the shorter frame length of this model. The engine was now mounted slightly further towards the front of the bike. The new rear shock became fully adjustable for both compression and rebound damping as well as pre-load and the shock picked up a rear rubber mounting. The fork diameter went up by 1mm and brake wise the factory reverted back to the old cast iron calipers which didn't bend under pressure and also didn't fade when hot. The new ignition dropped an igniter and pulser coil, there was now just one of each and the inner clutch hub now became a single piece unit to eliminate one reliability problem from previous years. The un-necessary neutral switch mounting disappeared

TZ250J

The "J" of 1982 was virtually identical to the previous model apart from a few minor "glitches" being sorted out from the "H".

Yamaha TZ250J



TZ250T

The "T" of 1987.

1987 Yamaha TZ250T in White
1987 Yamaha TZ250T in White
1987 Yamaha TZ250T in White
1987 Yamaha TZ250T in White
1987 Yamaha TZ250T in White


TZ250A

1990 Yamaha TZ250A

Marboro Team Roberts machine ridden to second place in the Unlimited Class of Formula USA by Rich Oliver. The "A" model was the last model to use the parallel twin motor design. The following year the motor was completely re-designed in a v-twin configuration.


1992 TZ250D

1992 Yamaha TZ250D

Colin Edwards rode this Yamaha to win the American Motorcycle Association Road Racing 250cc Championship in 1992. This model has a v-twin engine design, a departure from the traditional parallel twin motors that had been used since the mid 1960s. The V-twin is narrower, and has less vibration, so the chassis can be made smaller and lighter. Another bonus is that the design gives more freedom to cylinder port design.


1998 TZ250 4TW

TZ250K


2002

2002 Yamaha TZ250

With the ban on two cycle motors for street use, the American Motorcycle Association decided to discontinued the 250cc road racing class at the end of 2004. Californian Rich Oliver proceeded to win every 250cc race in the final year on this machine, including the very last 250 AMA race which took place at Barber Motorsports Park.

TZ250 Specifications

TZ 250                                    
Specifications                                    
                                     
MODEL     TZ 250 A    TZ 250 B      TZ250 C      TZ250 D     TZ 250 E      TZ250 F    TZ 250 G     TZ 250 H     TZ 250 J
                                   
Year   1973   1974   1976   1977   1978   1979   1980   1981   1982
Model Code from   DS7/ 430-991101   DS7/ 430-991471   DS7/ 430-993101   DS7/ 430-994101   DS7/ 430-995101   DS7/ 430-997101   4A1/ 000101   5F7/ 000101    
Bore (mm)   54   54   54   54   54   54   54.25   56   56
Stroke (mm)   54   54   54   54   54   54   54   50.7   50.7
Capacity (cc)   247   247   247   247   247   247   249   249   249
Compression ratio   7.6   7.6   7.85   7.8   7.8   7.8   7.6   7.6   7.6
bhp   51   51   52   53   53   53   55   57   57
   @ rpm   10,500   10,500   10,500   10,500   10,500   10,500   11,500   11,000   11,000
Ignition type                         CDI                         CDI                         CDI                         CDI                         CDI                         CDI                         CDI                         CDI                         CDI
Timing (mm btdc)   2   2   2   2   2   2   2   2   2
Carburettor       Mikuni VM34SC     Mikuni VM34SC     Mikuni VM34SC     Mikuni VM34SC     Mikuni VM34SC     Mikuni VM34SC     Mikuni VM34SC         Mikuni VM36   Mikuni VM36
Primary Drive   3.35   3.35   3.35   3.35   3.35   3.35   3.35   3.15   3.15
Final Drive   34 / 16   34 / 16   34 / 16   34 / 16   34 / 16   34 / 16   34 / 16   35 / 17   35 / 17
6th gear ratio   0.81   0.81   0.81   0.81   0.81   0.81   0.81   0.91   0.91
5th gear ratio   0.87   0.87   0.87   0.87   0.87   0.87   0.87   0.96   0.96
4th gear ratio   0.96   0.96   0.96   0.96   0.96   0.96   0.96   1.08   1.08
3rd gear ratio   1.13   1.13   1.13   1.13   1.13   1.13   1.13   1.26   1.26
2nd gear ratio   1.42   1.42   1.42   1.42   1.42   1.42   1.42   1.56   1.56
1st gear ratio   1.93   1.93   1.93   1.93   1.93   1.93   1.93   2.07   2.07
Over-all top gear ratio   5.78   5.78   5.78   5.78   5.78   5.78   5.78   5.92   5.92
Fuel capacity   23   23   23   23   23   23   23   23.5   23.5
Gearbox oil capacity   1,700 cc   1,700 cc   1,700 cc   1,700 cc   1,700 cc   1,700 cc   1,700 cc   900cc   900cc
Front tyre   2.75" x 18"   2.75" x 18"   2.75" x 18"   2.75" x 18"   2.75" x 18"   2.75" x 18"   3.0" x 18"   3.0" x 18"   3.0" x 18"
Rear tyre   3.0" x 18"   3.0" x 18"   3.0" x 18"   3.0" x 18"   3.0" x 18"   3.0" x 18"   3.5" x 18"   3.75" x 18"   3.75" x 18"
Front brake   2 x Twin L-Shoe   2 x Twin L-Shoe   Disc   Disc   Disc   Disc   Disc   Disc   Disc
Rear brake   1 x Single L-Shoe 1 x Single L-Shoe Disc   Disc   Disc   Disc   Disc   Disc   Disc
Rear suspension   Twin Shock   Twin Shock   Mono-shock   Mono-shock   Mono-shock   Mono-shock   Mono-shock   Mono-shock   Mono-shock
Wheelbase (mm)   1,300   1,300   1,315   1,315   1,315   1,320   1,320   1,320   1,320
Width (mm)   510   510   630   630   630   630   630   615   615
Length (mm)   1,940   1,940   1,930   1,930   1,930   1,935   1,935   1,950   1,950
Rake (degrees)   27.5   27.5   27.5   27.5   27.5   26   26   24.5   24.5
Trail (mm)   90   90   74   74   74   97   92   87   87
Dry weight   110   110   118   118   118   107   107   106   106

External Links

'Yamaha TZ250'
Manufacturer
[[Yamaha]]
Also called TZ 250
Production 2002
Class [[:Category:Racing motorcycles|Racing]] [[Category:Racing motorcycles]]
Engine
v2, two-stroke
Bore / Stroke 56.0mm x 50.7mm
Horsepower 85.02 HP (63.4 KW) @ 12250RPM
Torque 36.88 ft/lbs (50.0 Nm) @ 11750RPM
Battery 8.2:1
Brakes Front: dual disc
Rear: single disc
Front Tire 120/60-r17
Rear Tire 165/55-r17
Wheelbase 52.95 inches (1345 mm)
Length 77.05 inches (1957 mm)
Width 25.59 inches (650 mm)
Height 42.4 inches (1077 mm)
Seat Height 30.43 inches (773 mm)
Weight 229.28 pounds (104.0 Kg) (dry),
Manuals Service Manual


The Yamaha TZ250 was a v2, two-stroke Racing motorcycle produced by Yamaha in 2002. Max torque was 36.88 ft/lbs (50.0 Nm) @ 11750 RPM. Claimed horsepower was 85.02 HP (63.4 KW) @ 12250 RPM.

Engine

The engine was a liquid cooled v2, two-stroke. A 56.0mm bore x 50.7mm stroke result in a displacement of just 249.0 cubic centimeters.

Chassis

It came with a 120/60-r17 front tire and a 165/55-r17 rear tire. Stopping was achieved via dual disc in the front and a single disc in the rear. The bike weighed just 229.28 pounds (104.0 Kg). The wheelbase was 52.95 inches (1345 mm) long.

In Media