Neglected 4-stroke Bottom Ends

1. Œ We are now well into our second decade of high performance 4-stroke motocross bikes and their derivatives. Most folks have become accustomed to the maintenance-needy valve train components and small oil change intervals. The titanium valves cost an arm and a leg and the short skirt pistons don’t endure for long. That is

Yamaha V-Max and V-4 Valve Clearance

The Yamaha V-Max showed up in 1985 and ran for more than 20 years in its first generation form. Derivatives of this V-4 engine were also used in the Venture, Venture Royale and Royal Star models. The firing order of this engine is cylinder: #1 (0°), #3 (180°), #2 (430°), #4 (610°). There is a