Hi folks,
A friend of mine's got a YZF 750 that he's running in Classic Superbike racing. Lately it's been acting up: starts & idles fine but refuses to take full throttle, popping & banging on the overrun, rev counter needle jumping about. At a recent meeting the problem was particularly bad, forcing a retirement. Back in the pits the plugs were changed, EXUP valve disconnected & wired open, problem still persisted. A faulty ignition pickup,s been suggested, any ideas?