Cam chain 650

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fossie
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Cam chain 650

Post by fossie » Mon Dec 10, 2012 10:46 pm

Finally got a bit of time yesterday to do a bit on the German 650.
After I fitted the cleaned carbs a few months ago, it started and ran but cyl 3 and 4 didn't, get as hot as the other 2, so I was going to balance the carbs, but first do the shims.
On taking cam cover off, I noticed the front cam notch [at end) was not as level as the rear when they are set to open valves. However more important is the cam chain was the correct tension but when the crank nut was turned the chain was slack , then tight,then slack,tight ,etc.."". Any ideas?
To be honest when it was running there was a buzzing noise from that area, but it went at revs, but came back.
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Pedda
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Re: Cam chain 650

Post by Pedda » Tue Dec 11, 2012 1:03 pm

Maybe the chain got lengtheded unevenly by some reason. Very strange, that is. You should be able to prove by taking measurements when slack and when tight. Also the chain tensioner seems stuck.

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Re: Cam chain 650

Post by FBJ » Tue Dec 11, 2012 1:37 pm

Aint there a tensioner blade in the rocker cover? I would just reset the cam timing and follow the correct process to tension the chain

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Re: Cam chain 650

Post by sparki » Tue Dec 11, 2012 2:15 pm

yeah.... maybe pop pff the tensioner and see if it moves freely..... give it a service and stick it back on
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Re: Cam chain 650

Post by fossie » Tue Dec 11, 2012 8:34 pm

Cheers that is the next step, though I did flick the wheel thing and it is free and springs back.
The 650 dosen't have a blade on the cover however.

I like pedda feel maybe the chain has been stuck in 1 position for a long time and when the motor has been turned over I stretched. But if the cam is not set correct it may mean that the engine has had the top off and the chain was trapped?
Gonna have to be a new chain and tensioner really , what do you think.?
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