Difference between revisions of "Moped"

By the 1980s, it was obvious that the pedals on mopeds were no longer performing any useful function, in fact the performance of the {{convert|49|cc|1|lk=on}} engines available was delivering speeds in excess of {{convert|80|km/h|-1|lk=on}},{{Citation needed|date=January 2010}} a common model in the UK being the [[Yamaha FS1E]].{{Citation needed|date=January 2010}}  Due to emerging safety concerns that resulted from the considerably greater speeds that newer mopeds were capable of reaching, western jurisdictions introduced new regulations (eg UK in 1977)[http://www.classicbikepictures.co.uk/c319/p2117/yamaha%C2%A0fs1e.html Yamaha FS1E Classic Bike Pictures]{{Citation broken|date=January 2010}}, limiting the speed of these "mopeds" to {{convert|30|mph|0}} (and abolishing the requirement for pedals).{{Citation needed|date=January 2010}}  In some cases, the power restrictions (such as perforated plates in the inlet tract) were primitive and easy to bypass,{{opinion}} but the larger manufacturers such as those from Japan restricted engine breathing with smaller carburetors (eg {{convert|16|mm|2|lk=on}} replaced with {{convert|13|mm|2}}) and modifications to cylinder ports and exhausts.{{Citation needed|date=January 2010}}  Then they fitted [[CDI]] ignition systems tuned to limit maximum engine revolutions; the [[Honda MT50|Honda MT/MB50]] was built to run to 10,000 rpm, but the combined restrictions cause it to run out at around 6,500 rpm.{{Citation needed|date=January 2010}} Illegal de-restriction of such models is extremely difficult, requiring replacement of piston, barrel, carburetor and CDI electrics, and possibly the crankshaft and the exhaust as well.