Valve Clearances-need an ideal

[wallabear]

Ok I will try to keep this brief. I spent last night adjusting the valve clearances on my 2002 400ex. I did it all by the book but now the problem seems to be worse. . .

When I first start of the bike it seems fine but after warming up the valves made some niose. After doing a bit of extensive research I decided to check the valve clearances. I set the motor to TDC and made the necessary adjustments. they were a bit wide. After I got the bike back together enough to start I fired it up to see if that fixed the problem. Much to my dismay the valve were still off but now worse. They seem to be hitting the top of the head. I have a few ideals on what it could be but I want to get others opinions on what it could be before I tear down the head completely. I will be trying to re-adjust them this weekend again.worse

[duke416ex]

Sometimes the right side exhaust valve is annoying, you may have to give the engine a little jerk as you turn it to loosen it up. It is usually the one that gives trouble on the bikes I have messed with. Are you using metric gauges or standard?

[wallabear]

I am using a standard gage .004 intake and .005 exhaust. the gages are marked with metric though. Thinking back I am woundering if I had the engine TDC in the wrong stroke though. Would that cause the really harsh wrapping?

[400exrider707]

Originally posted by wallabear
I am using a standard gage .004 intake and .005 exhaust. the gages are marked with metric though. Thinking back I am woundering if I had the engine TDC in the wrong stroke though. Would that cause the really harsh wrapping?

yes yes it would! The only solution is to put it at TDC and take the valve cover off to see if the lobes are pointing down, then reinstall and readjust the valves, with the lobes for sure pointing down.

[300exOH]

I agree with ^^^. You will know you are at TDC when the rocker arms are loose on both the intake and exhaust valves.

[wallabear]

ok then I am pretty sure that is the problem then I will have to look at that on either Wendsday or Friday. I will let you know what happens

[400exrider707]

Originally posted by 300exOH
I agree with ^^^. You will know you are at TDC when the rocker arms are loose on both the intake and exhaust valves.

The only problem there is if he already adjusted on the wrong TDC he is going to have to remove the valve cover to find the correct one.

[300exOH]

Originally posted by 400exrider707
The only problem there is if he already adjusted on the wrong TDC he is going to have to remove the valve cover to find the correct one.

True. It's no problem though since he may have to readjust the valves anyhow if he wasn't at TDC when he adjusted them the first time.

[wallabear]

I was at TDC. I took the side cover off of the motor. turned the crank CC until the "T" mark lined up then adjusted the valve clearances. What I did not take into account was that I was at TDC of the wrong stroke. Correct me if I am wrong but it is possible to be at TDC on the compression stroke and TDC on the intake stroke. Unless the mark on the fly wheel only dictates one TDC meaning that: Starting with the "T" lined up, on the intake stroke. You rotate the fly wheel 1 full rev lining up the "T" up again. Is that the TDC of a new intake stroke or is it the TDC of the compression stroke. I believe that there are 2 TDCs' one compression and one intake. Am I wrong?

[300exOH]

Originally posted by wallabear
I was at TDC. I took the side cover off of the motor. turned the crank CC until the "T" mark lined up then adjusted the valve clearances. What I did not take into account was that I was at TDC of the wrong stroke. Correct me if I am wrong but it is possible to be at TDC on the compression stroke and TDC on the intake stroke. Unless the mark on the fly wheel only dictates one TDC meaning that: Starting with the "T" lined up, on the intake stroke. You rotate the fly wheel 1 full rev lining up the "T" up again. Is that the TDC of a new intake stroke or is it the TDC of the compression stroke. I believe that there are 2 TDCs' one compression and one intake. Am I wrong?

Yes. There are 2 TDC's but I believe all 4 rockers will only have play when at the correct TDC(compression stroke). You can double check your procedure here http://www.atvriders.com/articles/valveadjustment400ex.html

[knelson]

when you set your clearances cycle the motor around a couple of times and recheck,

[knelson]

by hand and I would suggest you use a breaker bar instead of a ratchet so it doesnt cycle over on it's own and tap a vavle if you are too tight.

[wallabear]

Thanks guys I got it adjusted. I had to the motor set to the wrong TDC. I got it up and running on Saturday. It made a BIG difference in the way it ran. My thenks to all of you who offered advice.