Ignition timing is typically split into three types. The first is initial timing—that is, the amount of spark lead that is set using a timing light (aimed at the harmonic balancer) with the engine at ...

Duvernay has the highest stock output production Quad 4: the 190-hp 1991 to 1992 RPO W41. The 1993 W41 lost 10 hp due to smaller exhaust ports. Photo: Kevin Davis via Wikipedia (CC-3.0) A 1992 ...