08 CR450R Decompression issues?

I've searched through other threads and can't find this issue. Or maybe I have and haven't done the work... anyway, here's the problem.

- the cam chain tensioner broke on my bike. It died but I was close to the truck and pushed it back. When I checked everything, it had jumped 1 tooth on the cam sprocket. No problem, I corrected that and put a new tensioner on it.

- Start it up and it's making noise in the top end but goes away after a minute or so of warm up. Kill it, go to start it again later but it has way too much compression. Push it past the hard part, then it starts again... same noise. Look online, find out it must be a broken decompression shaft.

- Pull it apart again, inspect the decompression shaft and it appears to be working correctly. Put it back together, start it and ride it a bit. If it dies while it's hot, it's hard to start and it has the compression issue again.

- What could the problem be? Can the decompression shaft be bent? Could it stick and cause these problems? Should I break down and replace the decompression shaft anyway?

Any and all suggestions will be welcomed.

Thanks,

Darren

your cam jumped timing. Retime it

your cam jumped timing. Retime it

I thought I had it correct after it jumped. I'll check it again and see if that's the issue. It makes sense given the issues...

I've searched through other threads and can't find this issue. Or maybe I have and haven't done the work... anyway, here's the problem.

- the cam chain tensioner broke on my bike. It died but I was close to the truck and pushed it back. When I checked everything, it had jumped 1 tooth on the cam sprocket. No problem, I corrected that and put a new tensioner on it.

- Start it up and it's making noise in the top end but goes away after a minute or so of warm up. Kill it, go to start it again later but it has way too much compression. Push it past the hard part, then it starts again... same noise. Look online, find out it must be a broken decompression shaft.

- Pull it apart again, inspect the decompression shaft and it appears to be working correctly. Put it back together, start it and ride it a bit. If it dies while it's hot, it's hard to start and it has the compression issue again.

- What could the problem be? Can the decompression shaft be bent? Could it stick and cause these problems? Should I break down and replace the decompression shaft anyway?

Any and all suggestions will be welcomed.

Thanks,

Darren

And once you do get it in time , you need to make your tensioner lock into a manuel one ( no need to ever buy one )

because your new stock one will just jump again---------all tensioner need to be locked and not automatic:thumbsup:

And once you do get it in time , you need to make your tensioner lock into a manuel one ( no need to ever buy one )

because your new stock one will just jump again---------all tensioner need to be locked and not automatic:thumbsup:

Reset the timing and, like magic, it works perfectly. I love tearing into a top end as much as the next guy (NOT!) but I'm so happy to finally have this issue resolved. :busted:

Is there a way to turn my stock tensioner into a manual one or do I need to buy one like the Tokyo Mods cam chain tensioner?

Reset the timing and, like magic, it works perfectly. I love tearing into a top end as much as the next guy (NOT!) but I'm so happy to finally have this issue resolved. :thumbsup:

Is there a way to turn my stock tensioner into a manual one or do I need to buy one like the Tokyo Mods cam chain tensioner?

If you do a search in the 250 CRF forum I have pics and explain how to turn your stock tensioner into a manuel one ,

I do not really like some of the manuel tensioners you buy ----they show you have done something to your bike , ---they get in the way badly when doing jetting or carb cleaning ----and they look goddy.

nothing better than a sleeper where no one knows what inside your bike.

All the national bikes I do as well as all that I don't do , all have jamed tensioners that use the stock assemblies .

It all looks clean, stock and normal -----but they are not :busted:

Thanks for all the help!

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