To forum,
I am new to the group but hope to contribute helpful advice whenever possible. I currently own a 2000 ds650 with full ct Race exhaust, K&N airfilter, What is the highest lift camshaft I can use without buying the shim under bucket setup (350.00) and are these necesary ? What year models are the motor components interchangeable( cylinder,piston,camshafts,cylinderhead) ? Thanks

 

Welcome to the forums.

It is my belief that no cam requires the shim unders. It is merely insurance. Any and all cams can float a valve at a certain rpm, but the shim unders help to hold the valve is the off chance it happens.

But my experience is a web 109 cam can last a very long time with just dual rate valve springs, and a moderate rev limit. Heck I got a 109 camed motor with dual rates, no rev limiter, spraying nitrous in its second season with no issues. I dont advise that, but its possible.

If you go with more lift and less duration, the more you need to worry. Or add no limiter, and miss a shift, and that could be what it takes.

So my moral, do what you can afford, but give yourself some insurance on your investment. Shim unders, or a rev limit. The bigger the cam, the lower the limit.


Good luck.