[WillCRF]

Earlier this year I bought both my boys used '02 XR100's. Assuming the valves had never been serviced, I decided to check both. The Haynes manual I have stated a clearance on both valves at .05mm.

When I check the gap, both valves on both bikes were very tight. I adjusted them to .05mm per the manual. The bikes fired up probably easier than before. What has me second guessing myself is you can hear the rocker arms / valves clicking at idle speed. Never noticed that sound prior to making the adjustment.

Went back in on one of the bikes to double check my work. Both intake and exhaust clearance was right at .05mm. Fired it back up and heard that valve noise. Is this normal for the XR / CRF100's? Can anyone confirm .05mm as the right gap?

Thanks,

Will

[crfsonly]

will...0.05 is the correct valve clearance. did you allow it to warm to operating temperature? the valve train will expand at operating temps and will consume some of that clearance and hence the rocker noise. you might also check your valve chain tension...this can also add to the noise. they do stretch over time so it could need some attention as well.

good luck....ken

[WillCRF]

Ken,

Thanks for confirming the gap setting. We are off tomorrow for a two day riding trip since we have a heat wave here in the Mid-West; well mid 50's but it is all relative. I will see if the valve noise softens after they have gotten good and warm. Will also check the tension on the timing chain when I get home.

Happy Holidays,

Will

[WillCRF]

you might also check your valve chain tension...this can also add to the noise. they do stretch over time so it could need some attention as well

Ken,

Took your advise and checked the chain tension. The upper adjustment provided no improvement. Went to the lower adjustment point (not sure what these are really called) and tightened the tension.

It made an improvement in the noise but I can still hear the vales when the XR100 is at idle speed. Now I know it is hard to describe in writing what I am hearing. With that said, is it normal to hear slight valve clatter when at idle? When I adjusted the valves, I went back a second time to check my work. Since we have put about 150 miles on the bikes and the XR100's are running great.

Any thoughts?

Will