Shim Question

I have an 03 CRF 450 that I bought used. It has been hard to start since I got it when cold. I know the previous owner never did anything valve related to it. So, I checked my valves and they were all in spec except for the right side intake valve (brake side), which from what I understand is rare. I couldn't get the smallest feeler gauge to slide through, which was a .0015. I'm not sure if it was because it was to big still or just to flimsy. Either way, the valve is close to zeroed out.

I took out the cam and now I need to replace the stock shim. My question is, do I just replace the shim with one that is .004 to .006 smaller? Thanks for the help and/or advice.:thumbsup:

If you buy a shim kit they will come in .05 incremants, like 1.80, 1.75, 1.70.

If you go to the dealer you can get them in .025 incremants.

Every .05 shim will move the gap .002, going down 3 of the .05 shims will move the gap .006.

Most times this works, but if the valve is really bad you`ll have to drop it even more. But i would replace the shim with one that 3 .05 sizes smaller and go from there.

I would go with .006 smaller and see where that gets you. If you get it into spec., check it again after 3-4 hours. My '03 lost about .004 clearance every couple hours until I decided to replace the valves. Good luck.

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