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I want to bump the CR on one of my R75/5 engines. It has a freash top end 10,000 miles ago with new 1st over 9:1 KS pistons.

I plan on removing the stock .5mm cylinder base gasket which should put me up in the 9.5:1 range. Aside from measuring the squish band and valve clearance is there anything else I should be aware of?

Any other comments welcome.

Garnet wrote:I want to bump the CR on one of my R75/5 engines. It has a freash top end 10,000 miles ago with new 1st over 9:1 KS pistons.

I plan on removing the stock .5mm cylinder base gasket which should put me up in the 9.5:1 range. Aside from measuring the squish band and valve clearance is there anything else I should be aware of?

Any other comments welcome.

I've seen this done on /5's and early /6's. Squish band and minimum valve clearance check, check and check again.
That's a 308 cam on your R75/5 right?

mattcfish wrote: That's a 308 cam on your R75/5 right?

Yes, at original 0 timing.