KX100 big bore 107

I was told that I can run a bigger piston at now extra cost since I am already having the cylinder redone. What about the power valve? Will it need to be recut?

check for clearance but on my bike(bored 100) my engine builder shaved the valve

So did you send him the cylinder with the PV in place?

yer the whole motor was there as it was getting the bottom end done as wel

I read on another site that the 100 is already over square and that the bigger piston puts more stress on the crank. I was just thinking that more cc's would help out my son offroad wise. More torqe, but since its already a big bored 85 maybe I should just redo it stock.

I am in the process of doing my sons into a 107as well. And the answer to the PV Q, is yes, The PV only sits about 1.5-2mm from the cylinder wall, stock. Going to a 54.5mm bore will definately put the PV in the bore.

If your worried about stress on the crank and you're having the bottom end rebuilt, Get a Hotrods assembly = no worries.

Don't forget to jet for it too. You run it lean??? and kaboom!

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