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Assessing the damage 08 650. no valve shims still does not clear within spec

4887 Views 89 Replies 21 Participants Last post by  Rehcie
So while doing my valve clearance on a new to me bike, it seems as though the front cylinder was especially friction-y. I measured 0 clearance.

When I took of the chain tensioner, the chain remained super tight, which made me think that possibly the Valves are really jammed against the camshaft.

Took off the camshaft journal and had to criss cross the screws for much longer than the rear head, the camshaft was really pressed tight against the journal. Pulled the tappet to check the numbers on the shim, noticed they were actually super worn and had lots of wear marks. Sounds like loose valve symptoms right? Well....

For kicks I reinstalled the tappets without any shims. Timed the chain and camshaft, reinstalled chain tensioner.

Turn over the crankshaft twice and measure clearance...not within spec sadly. Couldn't fit 0.10mm.

New valve time, right? Anything else this could be?

Bike runs "great" but the front head is noisy. Sounds slappy and has a loud ring to it upon startup

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Removed the shims? Have to have something in there. Pictures would be good of the keepers. Exhaust or Intake?

Sounds like a keeper or valve is bad. Shims help keep the keepers in place!
70,000 miles for the first valve clearance check was too long. Not sure of the service history.

It will probably sort of work but the keepers will probably pop out while riding now.

It's your bike, you can do what you want with it. I see you got it used from someone else.

You came to the right place for help though. (y)

You could do a leak down test or compression check next to see if a valve seat is burned.
Yeah, it could be the camshaft journals are shot/burned too. What did they look like?

Don't get discouraged Mike, we are here to help! ;)
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Too bad you have to live in your van! :confused:

No shim and no clearance. I'm afraid that's the best you can do. Used fleabay cylinder head would be my next move.

I have no idea of your budget or current circumstances.
Two shims would have caused the valve to hit the piston me thinks. :unsure:

Don't think it's possible. Two shims on a valve would not stay in place. But, who knows?? A spring could be broken?

Should have no compression with two shims.

Let us know the real problem. I like root cause analysis! :geek:
Even if it wasn't at TDC I'd be screwed at 0 clearance. Its for sure at TDC and the cam timing is correct. I can fit the tappets in when it's off of TDC but not when it's at TDC
Yeah, this is confusing. Have clearance with the feeler gauge off TDC and no clearance at TDC?? :unsure:

Camshaft(s) could be bent!

Should have clearance most of the camshaft rotation. At least 180 degrees.

Service manual should tell you to how to check all the stuff you need. (y)
Well, it is your first time I assume and you are at least trying. :)

I probably made a lot of mistakes, but sometimes the you have to learn the hard way. We all have different circumstances.

All the info you need is probably here already.

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You can stick a cable tie down the top spark plug hole to see where TDC is also. Or a wooden stick, pencil etc. On top of the piston.

Then the lobes would have to be not touching the tappets too. Spin it around again if needed.

Yeah, need to get it going for the big trip! That's what it's all about. ;)
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Not sure how the shims got messed up. Number side goes up on the tappet (EDIT for correctness :) ) . Unless they popped out under the bucket. BAD.

Sure the tappets aren't scored? Once scored they can go bad fast. Like melt and burn through metal. Same with the cam lobes.
Stretched cam chains will mess you up too. So would a sheared key on the rotor to crank. Ignition advance keys...

There a many ways for this to go bad...

Wisdom thing.
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Big ride here we come. :cool:

This would have made the difference...

Gesture Font Circle Drawing Art

The cam lobes for the front cylinder are in position ‘A’ (if they’re not you’ll need to rotate the crank a further 360 degrees until they are).
The camshafts are now in the correct position to measure the front cylinder valve clearances. B is correct TDC on the rear cylinder head.
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So the front cylinder still sounds bad??? :unsure:
I'm not sure how I can upload a video here
Tapatalk with the cell phone maybe? Attach the file after uploading.

This is unacceptable! Need to fix before the big trip. (y)
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