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Valve Clearance Check - Shim Under Bucket

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Hi there,


I am looking to check my valve clearances on my CBR, as she is going on 35,000 miles soon, and I rather check it so I can forget about it, rather than have the clearances tighten up on me. I am about to complete Level 2 IMI Mechanic course, so I KINDA know what i am doing...


Shims are under bucket type... Haynes manual states to remove the cam chain tensioner just to check the clearance, but wouldn't that possibly give a false reading, as the chain tension off MIGHT allow the cams to raise clearance a little bit??


Also, wouldn't I get into trouble of the cam chain jumping a sprocket while turning the crank to get teh cam lobes off the buckets??


My thinking is, spark plugs out, valve cover off, check clearance, turn crank, check clearance, turn crank, etc etc, replace cover, order any shims I need and then find time to remove cams and change shims...


Any guidance will be appreciated.



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I have never hear about an engine where cam chain removal is required to check clearances. However, in order to find out what shims are hidden under the buckets, you may have to remove the cams, and hence alsot the chain. Unless, of course, you have already written down the size of the shims up front.


Personally, I much prefer the Kawasaki (and possibly others) way where you simply push the followers sideways to allow shim removal instead of having to remove the cams.

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Hi Eirik,


Yes Shims under buckets are a real pain, but I have what I have... I have no idea what shims are under there at the moment, but thanks for confirming that I can check the clearances without CCT removal...


Hopefully they are all within tolerance...

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CBRkid, I'm all with your method for checking the clearances. Haynes do foul things uorden in their manual. For the OEM manuals, they usually state "the proper way", which can be significantly different from "the experienced mechanic way", if you know what I mean :-P



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You do not need to remove the cam chain tensioner. The cam chain tensioner if mechanical is screwed in and offset with spring tension. All you should have to do is take side cover off to reveal the timing marks that line the crank up with top dead center. Rotate the crank through clockwise to the mark. Check your cams so that the intake cam "IN" mark is parallel with valve cover facing intake and exhaust cam "EX" mark is parallel with valve cover facing exhaust. You on a honda. You could wait another 35,000 miles :D

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