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I'm trying to help a guys from another site....

So any of you know har far you ca mill the head on a 98 CBR900RR? and still be safe to ride daily?

This guy wants to raise his compression even more!!! to squeeze out a little more power.

I wouldn't do it personally but if any of you guys know, I'd like to help him out.

Thanks
 

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I had the head shaved on my '99 CBR. I am not sure how much but I will ask my mech tomorrow. Actually he had the clinders shaved rather than the head. There is not enough space on the actual head. It does run a little hotter though.(I am now using Water Wetter and distiled water)
 

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i dont think there will be a problem with a small amount taken off. There are 5 ways to increase the compression ratio. Mill the head, which makes the cobustion chamber in the head smaller, using a thinner head gasket, which in effect makes the comustion chamber smaller in the head similar to milling the head but you are taking material out of the gasket rather than the head itself, use higher compression pistons, which will have more material on the top of them, boring the cylinder, which will increase the volume in the cylinder, and lastly decking the block. When you have the block decked most of the time you deck it to a zero dech height meaning that when the pistons are at TDC they are even with the block. The benefit in this is while the compression ratio is raised, also more of the combustion takes place in the head instead of the cylinder. In a moderate amount I dont think there would be a problem using atleast 1 of these methods to increase compression on any bike as long as the bike is tuned right so it doesnt run too hot.

http://webpages.charter.net/fullforce
 
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