New to the crf250r world, valve question

Hi everyone,

 

It seems valve questions have been beat to death around here but I have an issue I have not seen discussed here before.

 

I bought a 2008 250 a few days ago and even though it started and ran great, I decided to pull the valve cover off and see where the clearances were at. The valves were quiet but I still wanted to check to see if they had proper clearance. The exhaust valves were fine, both of them were right at .011. The intake valves were at .006 and .007. I decided to reshim and after putting the new shims in, they both measured at .005. After getting it back together it started up right away and runs great, but I noticed there is a significant ticking now. Why would it have a loud tick when the valves are spot on? Especially when it didn't tick before with looser valves...

 

Is it possible I did something wrong with the decompression part on the cam when putting it back in? Like I said, I haved oned this bike for 3 days and am not familiar with this engine at all yet. Just wondering if I made a common newbie mistake.

 

Any help would be appreciated.

U gotta line up the cam with the cylinder head. If u don't the cam rocker is gonna make contact. Try and find a owners manual

You sure any of the shims didn't fall out when re installing the cam ? Usually makes a very distinctive ticking sound. Also check timing is not a tooth off.

The lines on the cam sprocket are lined up with the cylinder head at TDC, so I'm pretty sure the timing is correct.

 

I will take it apart again and see if the shims got displaced.

 

Thanks for the help so far guys

The shim on the right side exhaust valve is missing. I didn't even mess with those ones. I am praying it is still somewhere up top. Otherwise this has turned into a nightmare.

 

Going to look for it now.

If the cam wasn't aligned correct. There is space for the valve lifter to slip

I got EXTREMELY lucky! the shim was sitting in a little pool of oil still in the head. I'm glad I shut it down right away after I heard the ticking earlier.

 

I believe I have the cam aligned correctly but please tell me if I missed something - The two lines on the sprocket are parallel with the cylinder head at tdc and the retaining clips in the cam holders are in the groves of the cam bearings. is there anything else I have to check when re-installing it?

if you pulled the cam out be sure to make sure the timing marks in the crankcase are lined up too

Glad I could help mate, and dont worry your not the first and won't be the last to do it. Sounds like you have it sussed out but next time you set your timing use the TDC marks on the flywheel as they are more accurate then the right side primary drive gear.

I guess I learned the hard way this time!

 

Good to know about the TDC marks on the flywheel.

 

Thanks for all the help guys, it runs and sounds great now.

Yes, you need to have both the marks on the cam aligned, AND the mark on the flywheel aligned before putting on the chain.

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