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post #21 of 28 (permalink) Old 03-31-2012, 12:03 PM
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Originally Posted by kevlh22 View Post
I just bought a 2002 400ex. The guy said he bored it one over, spent $600 on a top end rebuild and now it won't start. It will only sputter. I take it home and start looking at it. It seems to have good compression my compression gauge won't fit it. I look at the timing chain and put the motor at TDC. The cam has marks arent lining up. So I jump the timing chain one tooth on the cam gear. It still isnt quite lining up but it is a little closer. I put it back together and still will only sputter (little more consistant this time though) Do I need a new timing chain? Is it common for these chains to stretch? The timing marks on the cam gear are only off like 2mm. Should it still idle but rough? Any help will be greatly appreciated. Thanks!
When you say spent 600 on a rebuild, you did it? a shop did it?

If a shop did it take it back and make them fix that shit.

If you did it, did you readjust the valve lash?
when you readjusted the valve lash, you were in TDC compression stroke?

also why did you rebuild the top end ( yes it matters )
Let us know
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post #22 of 28 (permalink) Old 05-09-2012, 06:13 AM
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Ok, before you do anything else, remove the tappet cover and look right behind the cam lobe nearest to the sprocket. If there is a small 4mm hole with nothing in it, that's your problem. There must be a pin and spring in it to hold the anti reverse device on the camshaft. If the pin is not there, the device is turning with the cam and your right hand exhaust valve only closes every second turn. It sounds like the engine is firing only every second turn. Good luck.
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post #23 of 28 (permalink) Old 05-09-2012, 02:08 PM
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Originally Posted by Deon View Post
Ok, before you do anything else, remove the tappet cover and look right behind the cam lobe nearest to the sprocket. If there is a small 4mm hole with nothing in it, that's your problem. There must be a pin and spring in it to hold the anti reverse device on the camshaft. If the pin is not there, the device is turning with the cam and your right hand exhaust valve only closes every second turn. It sounds like the engine is firing only every second turn. Good luck.
Makes sense^^^^^ the decompression system if you cannot find the spring and plunger you may have to remove the cam and take the decomp system off.

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post #24 of 28 (permalink) Old 08-29-2012, 01:06 PM
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I had the same problem with my decompressor except mine was just missing the spring (50cents) from Honda shop put it back together and fired right up its very easy to miss it but it's right behind the cam gear I would bet my check that's what it is cause I got mine completely rebuilt and was doing the same thing good luck
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post #25 of 28 (permalink) Old 09-29-2012, 08:41 PM
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Originally Posted by Jabman View Post
So when you installed the timing chain, you made sure the slack of the chain was at the tensioner side? and the tight side of the chain was near the exhaust?
Then you put the cam sprocket back in with one tooth leaning towards the exhaust side?

when you do it this way, and put the tensioner back into place, it will pull the slack of the chain away from the cam sprocket down into the motor, aligning those marks where they need to be.

Its the same concept as the 22r yota motor.

Cheers
I am having the same d*** timing issue. I either have one line on the cam sprocket leaning towards the exhaust, or leaning towards the intake. I cannot get them to lineup correctly.

Would moving the chain one tooth on the crank fix this? Or do I just let one line hang on the exhaust side, with the slack on the intake side?

'05 Rancher AT (wifes ride)

'01 400ex - Custom air box, battery relocation, Trimmed fenders, Renthal bars, FMF can, 14 tooth front, 20" Mudlites out back.

Last edited by Deeperinthabush; 09-30-2012 at 12:31 AM. Reason: wording
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post #26 of 28 (permalink) Old 09-30-2012, 12:30 AM
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put the tensioner back into place, it will pull the slack of the chain away from the cam sprocket down into the motor, aligning those marks where they need to be.

Its the same concept as the 22r yota motor.

Cheers[/QUOTE]

I am having the same d*** timing issue. I either have one line on the cam sprocket leaning towards the exhaust, or leaning towards the intake. I cannot get them to lineup correctly.

Would moving the chain one tooth on the crank fix this? Or do I just let one line hang on the exhaust side, with the slack on the intake side?[/QUOTE]

Installing the timing tensioner is the only way to align the cam timing marks properly,and easily...

FREE REPAIR MANUALS >>http://www.hondaatvforums.net/forums...all-years.html 1986-1992 trx350 parts for sale>>http://www.hondaatvforums.net/forums/atv-parts-sale/29225-complete-part-out-1986-fourtrax-350-a.html
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post #27 of 28 (permalink) Old 09-30-2012, 09:17 PM
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Quote:
Originally Posted by Deeperinthabush View Post
put the tensioner back into place, it will pull the slack of the chain away from the cam sprocket down into the motor, aligning those marks where they need to be.

Its the same concept as the 22r yota motor.

Cheers
I am having the same d*** timing issue. I either have one line on the cam sprocket leaning towards the exhaust, or leaning towards the intake. I cannot get them to lineup correctly.

Would moving the chain one tooth on the crank fix this? Or do I just let one line hang on the exhaust side, with the slack on the intake side?[/QUOTE]

Installing the timing tensioner is the only way to align the cam timing marks properly,and easily...[/QUOTE]

Thanks for re-assuring me. I can attest that this in fact works. I had my right timing mark on the cam hanging down towards the exhaust, I put the tensioner in, put engine back together, and she's ALIVE.

Love this forum. I have built a few car engine in my time. and this just kind of weirded me out.

'05 Rancher AT (wifes ride)

'01 400ex - Custom air box, battery relocation, Trimmed fenders, Renthal bars, FMF can, 14 tooth front, 20" Mudlites out back.
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post #28 of 28 (permalink) Old 09-30-2012, 09:32 PM
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Thanks for re-assuring me. I can attest that this in fact works. I had my right timing mark on the cam hanging down towards the exhaust, I put the tensioner in, put engine back together, and she's ALIVE.

Love this forum. I have built a few car engine in my time. and this just kind of weirded me out.[/QUOTE]

You're welcome...

FREE REPAIR MANUALS >>http://www.hondaatvforums.net/forums...all-years.html 1986-1992 trx350 parts for sale>>http://www.hondaatvforums.net/forums/atv-parts-sale/29225-complete-part-out-1986-fourtrax-350-a.html
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