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So went to go do a valve clearance check on my 02 Honda 400ex I just purchased. Has 440 big bore kit , stage 2 hot cam as I seen from the valve cover the decompression stuff was not on the cam. ( previous owner said this was all done) has moded air box an full white brothers exhaust. Well heard a really loud ticking coming from the head so decided to check the clearances an both intake an exhaust valves were so tight couldn’t get .004 nor .005 gauge in at all. So I believe I had the engine at TDC I pulled the side covers out an rotated the crank till the marks lined up and went to adjust the valves got the exhaust ones done easy did the intakes an got one done an went to do the other but couldn’t get the gauge in what so ever even back the bolt an nut all the way out there still was not enough clearance to get the gauge in any one happen to know why? Still a pretty loud ticking sound was thinking could be the timing chain too but this one really tight intake valve has me a little worried. I’m gonna go over stick a straw down to the piston an rotate the crank to be 100% certain I’m at TDC an try again. ( doesn’t smoke , doesn’t have trouble idling, starts right up….
 

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2020 520 rubicon foot shift
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Here's a quick easy way to get to tdc to check valves.
With the valve cover excess bolts off the intake side watch the valves as you turn the motor over. Turn it over until the intake valves open then close, once the intake valves close fully set the clearance.

It's weird one intake valve is way tighter than the other, you may have a bigger issue than the valve clearance but I cant guess what.
 

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Honda RFVC engines are notorious for being noisy but too noisy is not a good thing. One valve being way tighter then the other is not good. Remember that if one intake valve is loose, the cam is in the right place. That ticking is either your cam chain or that one intake valve slamming into the piston. If I had to guess that one valve was not replaced when it's head was off and the other was. That valve has worn so much that it is now slamming into the piston. A worn valve + a more aggressive cam that throws the valves out more then stock could easily cause this. This is a lot easier of a fix then a dropped valve, etc. take the valve covers and head off, you'll be able to find out why its ticking. If the issue is the valve usually it requires only a valve aslong as that valve hasn't worn into the head, if it has, then replace the head.
 
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