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

4887 Views 89 Replies 21 Participants Last post by Rehcie, 3 mo ago

conquermike

Discussion Starter · 3 mo ago

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

Mike

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D.T.

· #2 · 3 mo ago (Edited)

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!

conquermike

Discussion Starter · #3 · 3 mo ago

D.T. said:
Removed the shims? Have to have something in there. Pictures would be good of the keepers.

Sounds like a keeper or valve is bad.

I'm confused why a shim needs to be in there

D.T.

· #4 · 3 mo ago (Edited)

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.

You could do a leak down test or compression check next to see if a valve seat is burned.

Dark Angel

· #5 · 3 mo ago

Are you absolutely sure the cam timing is correct? You got the front cylinder at TDC on compression? Something is direly wrong with your setup as it is.

Reactions: 1

D.T.

· #6 · 3 mo ago

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!

Reactions: 2

conquermike

Discussion Starter · #7 · 3 mo ago

D.T. said:
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.

You could do a leak down test or compression check next to see if a valve seat is burned.

Do you know what the minimum thickness of shim is that I can put in their to still operate the bike while I figure out how I'm going to fix it. I don't have a place to store the bike and live in my van, so I'm under pressure to put it back together and for it to at least work in the meantime

conquermike

Discussion Starter · #8 · 3 mo ago

D.T. said:
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!

I'll take pics of the journals, and for that matter I'll take pics of everything in there. I'm 100% sure it is timed and at TDC for the front cylinder, I can fit shims in when it's off TDC

D.T.

· #9 · 3 mo ago (Edited)

Too bad you have to live in your van!

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.

conquermike

Discussion Starter · #10 · 3 mo ago

Dark Angel said:
Are you absolutely sure the cam timing is correct? You got the front cylinder at TDC on compression? Something is direly wrong with your setup as it is.

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

conquermike

Discussion Starter · #11 · 3 mo ago

D.T. said:
Too bad you have to live in your van!

Don't get me wrong, best decision of my life! It's not a down on luck thing until a multi-day Mechanical project comes up 🤣 I've slept in my van while it's on jackstands during a tie rod and ball joint replacement odyssey

Reactions: 3

conquermike

Discussion Starter · #12 · 3 mo ago

D.T. said:
Too bad you have to live in your van!

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.

Just seeing your additions to your comment. Budget is not a concern, time is my only concern since I'm trying to leave asap for a 6k mile trip through Baja but don't want to blow up my engine obviously.

Looks like new Valves and camshafts are due at a minimum, as well as Compression and Leak down testing to see if everything else is fine. I've got the service repair manual to do some diagnostics, gonna check valve springs and such.

Reactions: 1

Dark Angel

· #13 · 3 mo ago

conquermike said:
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

What do you mean "fit the tappets in"?
The buckets can't come out from under the cam without removing them, and the shims are under the buckets.

Make sure somebody hasn't got two shims in there somehow.

Reactions: 2

conquermike

Discussion Starter · #14 · 3 mo ago

Dark Angel said:
What do you mean "fit the tappets in"?
The buckets can't come out from under the cam without removing them, and the shims are under the buckets.

Make sure somebody hasn't got two shims in there somehow.

Sorry I mispoke, I meant to say feeler guage will fit when the cylinder is off TDC

conquermike

Discussion Starter · #15 · 3 mo ago

conquermike said:
Sorry I mispoke, I meant to say feeler guage will fit when the cylinder is off TDC

Dark Angel said:
What do you mean "fit the tappets in"?
The buckets can't come out from under the cam without removing them, and the shims are under the buckets.

Make sure somebody hasn't got two shims in there somehow.

Will

Dark Angel said:
What do you mean "fit the tappets in"?
The buckets can't come out from under the cam without removing them, and the shims are under the buckets.

Make sure somebody hasn't got two shims in there somehow.

Good idea to check for two shims. worth a shot

D.T.

· #16 · 3 mo ago (Edited)

Two shims would have caused the valve to hit the piston me thinks.

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!

D.T.

· #17 · 3 mo ago (Edited)

conquermike said:
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??

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.

conquermike

Discussion Starter · #18 · 3 mo ago

D.T. said:
Yeah, this is confusing. Have clearance with the feeler gauge off TDC and no clearance at TDC??

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.

I think you may be contradicting yourself here; I mentioned I have clearance when I'm not at TDC, which you seem to think is confusing per your first sentence, but then we are in agreement when you say I should have clearance most of the camshaft rotation, which would be in agreement with what I said about having clearance when I'm off TDC.

conquermike

Discussion Starter · #19 · 3 mo ago

D.T. said:
Two shims would have caused the valve to hit the piston me thinks.

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!

So there's definitely only one shim, I took pics and video that I'll upload tomorrow. There are some super sticky parts of the crankshaft rotation where I can hear what sounds like decompression happening in the front cylinder (my problem cylinder). I'm gonna get a quote for an inspection from my local moto shop. something tells me a conclusion will not be reached by the time I want to leave in....9 days.

I'm considering ordering the tiniest shims and just riding it out for the 6k mile trip

Dark Angel

· #20 · 3 mo ago

I really wouldn't ride it like that. There's a high chance you'll stick a valve through the piston.

Reactions: 1

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