Cam Chain Guide Question for motorheads

[Anonymous]

This is a great site. I know there's some real knowledgeable motor guys here. Hope you can share some knowledge.

My '82 GS 1100EZ has 37,000 miles on it. I Bought it May of 2001 with 21,000 miles from the original owner. Bike has run great entire time.

It developed a pronounced whirring / grinding / rubbing sound in the engine which is constant with RPM's, whether in gear or not, clutch engaged or not, moving or not. It is not a valve click or a knock. At first the sound was intermittant, now its constant. Other than this noise, the bike runs fine.

I've isolated the clutch, its not the source of the noise. Head is off, and I am looking around.

I noticed the cam chain guide at the front of the engine (the straight one) has 1/16" raised groove down the middle.

The rear curved guide at the back of the engine (that the cam tensioner pushes against) barely has a raised groove at all. It also appears to have two sets of recessed grooves on each side, as if the chain may be running to one side or the other. Looks worn compared to the straight guide.

1) Could this apparently worn guide explain my noise? I cannot see any areas where the chain may have been rubbing against anything. The curved guide appears to be closer to the left side of the chain bay when at its normal position. It also has play from left to right when pivoted more towards the front of the engine. Is it possible that the chain may not be rubbing against anything metal but that the guide is against the side of the chain bay, transmitting the noise in that manner?

2) Is the rear curved guide supposed to have the same amount of raised groove as the straight guide to the front of the engine?

3) The rear curved guide has flat pads on either side which would appear to be for the purpose of keeping it rather fixed when in its normal position. Is it supposed to have any left to right play when tilted forward?

4) If I replace the rear curved chain guide, what's the best way to get the cylinder block broken free to remove it to get at the guide mounting bolt? The factory manual shows a splitter tool, but I don't have one.

5) Also wondering if the 'automatic' chain tensioner wasn't doing its job to cause this???

Appreciate any help or advise you've got.

[Anonymous]

Re: Cam Chain Guide Question for motorheads

This is a great site. I know there's some real knowledgeable motor guys here. Hope you can share some knowledge.

My '82 GS 1100EZ has 37,000 miles on it. I Bought it May of 2001 with 21,000 miles from the original owner. Bike has run great entire time.

It developed a pronounced whirring / grinding / rubbing sound in the engine which is constant with RPM's, whether in gear or not, clutch engaged or not, moving or not. It is not a valve click or a knock. At first the sound was intermittant, now its constant. Other than this noise, the bike runs fine.

I've isolated the clutch, its not the source of the noise. Head is off, and I am looking around.

I noticed the cam chain guide at the front of the engine (the straight one) has 1/16" raised groove down the middle.

The rear curved guide at the back of the engine (that the cam tensioner pushes against) barely has a raised groove at all. It also appears to have two sets of recessed grooves on each side, as if the chain may be running to one side or the other. Looks worn compared to the straight guide.

1) Could this apparently worn guide explain my noise? I cannot see any areas where the chain may have been rubbing against anything. The curved guide appears to be closer to the left side of the chain bay when at its normal position. It also has play from left to right when pivoted more towards the front of the engine. Is it possible that the chain may not be rubbing against anything metal but that the guide is against the side of the chain bay, transmitting the noise in that manner?

When I had my engine apart the rear guide (curved one) had grooves, however, I don't remember if they were apparent near the top. I don't remember anythign about the front one - just that it didn't look worn or I would have replaced it like the rear. If the chain is properly adjusted I don't think the front guide should move side to side at all.

2) Is the rear curved guide supposed to have the same amount of raised groove as the straight guide to the front of the engine?

My new guide had NO grooves in it. It was an aftermaket unit - not Suzuki.

3) The rear curved guide has flat pads on either side which would appear to be for the purpose of keeping it rather fixed when in its normal position. Is it supposed to have any left to right play when tilted forward?

It should have tension on the cam chain. It sounds like it's not adjusted properly.

4) If I replace the rear curved chain guide, what's the best way to get the cylinder block broken free to remove it to get at the guide mounting bolt? The factory manual shows a splitter tool, but I don't have one.

Once the head is off, the cylinder block should be free. If not, tap it with a rubber mallet. I split my cases so replacing the cam chain was a snap. If you don't spit them you need a chain with a master link.

5) Also wondering if the 'automatic' chain tensioner wasn't doing its job to cause this???

Your chain may be stretched to the point where the adjuster isn't capable of functioning properly. I installed a manual adjuster. If I was you I would at least inspect your old one if you are going with the automaic one.

Appreciate any help or advise you've got.

I'm sure others with chime in.

[earlfor]

The cam chain runs in an oil bath. I cannot imagine that it could be worn out in 37K miles. I recently had the cylinder head and barrels off of my 1150 to replace gaskets. The cam chain guides (front and back) (mine are stock suzuki) appear to have been made with the grooves in them. In any event, I strongly doubt they would contribute or cause the noise you hear. The most likely reason for the noisy camchain is the automatic tensioner needing servicing and not following the chain as precisely as it is supposed to.
I would remove the tensioner and clean it up and check for smooth operation of the internal rod and spring assembly. The tensioner rod should be locked for removal, and once the assembly is serviced, it should be "cocked" and locked. Then installed and unlocked, free play on the locking rod set and then locked in the free position. At no time should the external spring wound knurled wheel ever be turned by hand.

Earl

[SqDancerLynn1]

Things like this are hard to diag over the computer I would take a look at the starter, starter clutch