Checking Valve Clearance. Properly using feeler gauge?

Hey guys,

So this is probly a really stupid question, but I'm going to ask anyways because it's not making sense to me. I watched online on measuring valve clearance and I understand how to do it by taking the feeler and going under the cam lobe. My thing is.. none of my gauges fit.. For example the exhaust side on my bike calls for .20 - .25 to be in spec. I can take my .05 feeler and it doesnt fit. I cant see the valves being off this much. The bike is a 2012 YZ450F, with around 30 or 40 hours I would say. Its my first time checking valves since I bought it. Now when I use the feeler.. should it go all the way through the cam lobe and come out on the other side? because right now even the smallest feeler I have goes in about half way and stops. And yes its TDC and everything is correct and I can read decimals correctly. My guess is yes the feeler should go all the way through and have a slight drag when doing a back and forth motion. But I mean... damn... a .05 wont even fit??? thats crazy to me. Same goes for intake. It calls for .10 to a .15 for in tolerance. and my .05 wont fit. The bike ran fine and started in 1 or 2 kicks. Am I doing it wrong or should I get a smaller feeler gauge?

did you verifty the piston is in TDC?

oops i see u verified tdc.

Edited by szebo

not sure about other bikes, but hondas the TDC must be on the exhaust stroke. did u verify that its TDC on the correct stroke?

Ok got it! I only had the marks inside the ignition cover lined up, I didnt even think about the marks on the cam shaft LOL. I knew this was a dumb question. Valves looks good. 1 Exhaust valve was a tad under spec, but other than that shes at .10 for intake and .20 exhaust!

Thanks for the ideas guys. I didnt even think about those darn cam marks.

Edited by MotoSarge

yeah, u must have been in the wrong stroke.

This post does not belong the jetting area.

You do not have to even look at the flywheel matrks.

Remove the fuel tank, remove the spark plug. Put the bike in top gear and slowly roll it forward. When the cam lobes are at 2 and 10 o'clock, check the cleaances.

Sorry william. I didnt see an engine forum.

LOL, there is no generic engine forum. This one is 'as good as it gets'! :)

Glad you got it figured out.

Edited by singletracmind

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now