I tend to think the current Yamaha reliability is largely due to the five valve head design. Smaller, lighter valves have less inertia and use lighter springs. Think about where that design came from, its actually one slice of an older R1sport bike motor. Even their sleds use it now.
Steve,
I had a C'dale E440. Basic problem is they were too arrogant to progress slowly and learn how to produce an off road bike that works. Lots of thermal and electrical problems. The E440 was just the MX bike (very light flywheel)with a light and softer map, so when it got in the woods these issues that did not occur on the track reared their ugly head fast. Want to talk about re-engineering? I redesigned the entire power distribution system with SSRs and better noise supression, insulated the tank, airbox, fuel lines, ceramic coated header, etc., along with a LOT of custom mapping. The short header allowed blue flame out of the can you could see at night.
, and it was loud. The motor was mechanically loud too and sounded like a Ducati. I had no mechanical issues at all because I addressed the problems immmediately. In the end the bike was pretty good as long as it was not too tight. It would run with a CRF450 of that era because it hooked up so much better. They made real good SM bikes and awesome ice racers. I just got tired of working on it trying to make it something it was not. I sold it to a guy who made a street legal SM out of it. One thing though, that bike was built VERY well. The fit and finnish was top notch, no BS there.