Cam chain and adjuster

[Fjbj40]

Moved from here http://www.thegsresources.com/_forum/showthread.php?240697-Manual-cam-chain-tensioner-problem .

So I removed and checked my factory cam chain tensioner. It was rebuilt and functions properly. I was getting a noise which sounds like cam chain noise but with a light knocking sound.

Upon on removal I realized the auto tensioner was extended all the way, and I mean ALL the way. It was installed properly with lock screw turned out 1/4 - 1/2 turn after install.

There is a new rear cam chain guide installed, cam chain was measured while engine was disassembled and was below max wear limit. How much below you ask? About .040". Still below limit I said so I will not replace it.

BIG MISTAKE!

After playing with the tensioner tonight it functions perfectly. I did however figure out that when it is at its max outward travel it will free play "in" about .100".

So so I am figuring with cam chain worn "close" to max limit, the tensioner is compressing and causing the light knocking noise from the cam chain as it slaps because the tensioner is moving in.

It it moves in because when it is all the way extended the roller ball in the adjuster is not touching the ramped slope on the adjuster plunger, thereby moving the plunger in and out causing chain slackness and noise.

Make sense?

Guess I am going to order a new chain from APE and pull this freshly assembled engine with 10 minutes of running apart, again! F A C K

 

[tkent02]

Guess I am going to order a new chain from APE and pull this freshly assembled engine with 10 minutes of running apart, again! F A C K

Not sure why you'd pull the engine apart to change a tensioner, it's on the outside.

 

[Fjbj40]

Not sure why you'd pull the engine apart to change a tensioner, it's on the outside.

Yes it is, but the chain is inside, one continuous loop around the crank. Read more carefully

 

[Steve]

On the other hand, YOU might be the one to "read more carefully". It is very common to mis-read the directions for installing the tensioner. :-k

You mentioned that "Upon on removal I realized the auto tensioner was extended all the way". Did you lock the tensioner in place before removal? If not, OF COURSE it's going to extend all the way when you remove it. :-\\\

If the tensioner is assembled and installed correctly, there is NO way that it will "freeplay". I think you have some other issues at hand, but if you really insist on going straight to the cam chain replacement, ... have fun. :encouragement:

.

 

[tkent02]

Yes it is, but the chain is inside, one continuous loop around the crank. Read more carefully

I can read just fine, you say your getting a manual tensioner because the automatic one isn't tightening the chain all the way, even though the chain is still within limits, so why replace the chain?

Actually I couldn't care less, pull the engine apart.

 

[Fjbj40]

On the other hand, YOU might be the one to "read more carefully". It is very common to mis-read the directions for installing the tensioner. :-k

You mentioned that "Upon on removal I realized the auto tensioner was extended all the way". Did you lock the tensioner in place before removal? If not, OF COURSE it's going to extend all the way when you remove it. :-\\\

If the tensioner is assembled and installed correctly, there is NO way that it will "freeplay". I think you have some other issues at hand, but if you really insist on going straight to the cam chain replacement, ... have fun. :encouragement:

.

Thats correct, extended all the way, and yes, set screw was tightened prior to removal.:-\\\ I probably spend more time reading manuals and following manufacturers instructions than the majority of the people on this forum do, in my trade I am legally responsible to do that. So ya, I can read instructions

Despite what you think you may know, if the plunger is extended to the full out travel, you know the little cut away on the plunger that the set screw makes contact with and is also the travel range for the plunger, it WILL have "freeplay".

The ball on the auto adjuster is not in contact with the plunger when the plunger is fully extended, play with an adjuster, you will see what I mean.

So so if you think I have some other issues at hand, tell me what are they? Seriously I am open to suggestions, learning something new.

So with a new Suzuki rear guide, all other parts installed correctly, chain pretty much at its wear limit, why is the plunger fully extended?

Just so so you know I have talked with one of the smarter professionals on this forum and he said it is the chain because it is near its limit.

 

[Fjbj40]

I can read just fine, you say your getting a manual tensioner because the automatic one isn't tightening the chain all the way, even though the chain is still within limits, so why replace the chain?

Actually I couldn't care less, pull the engine apart.

Nope, you still have not completely read everything, I already have the manual adjuster, it is also unable to do its job because of the near max limit chain.

Just so you know, if I take this all apart and find a Fawke up on my behalf I will report back so somebody else will learn from my stupidity and errors.

Have a good fight T

 

[geol]

Wow. You got roasted. Only thing I can think of is that your chain measurement was not correct.
Usually you are supposed to measure a certain number of links over a certain distance and that is
how you check to see if the chain is stretched. I used to race a GS1100 but that was 35 years
ago and don't remember for sure but I think the cam chain is a bicycle chain type affair and I also
think you can install a new chain with a master link. This would eliminate the chain as a culprit.
The master link is NOT like the master link used on a drive chain. This guy needs have the plate
go over the pins and then you stake the ends of the pins (just like they do at the factory on an
endless chain) and are pretty safe to use. Some folks are put off by the master link chain but
I have never had a problem with one and have used a number of them over the years. Staking the
chain is a bit of a challenge when the head is on the bike as you will have to have some unwitting
assistant hold a backing as you have to whack the pins pretty hard using a punch.

If you are positive the current chain is the correct length, you can always find a stainless steel bolt
longer than the thing that is in your manual tensioner but I am guessing if its tensioning screw is not
long enough and the Suz manual tensioner are not long enough then the chain is likely stretched.
Not sure how you could install cam chain bumper bits and such wrong and if the bike runs OK then
the chain is obviously circling the bottom sprocket just fine. Anyway, let us know how this works out.

 

[Fjbj40]

Wow. You got roasted. Only thing I can think of is that your chain measurement was not correct.
Usually you are supposed to measure a certain number of links over a certain distance and that is
how you check to see if the chain is stretched. I used to race a GS1100 but that was 35 years
ago and don't remember for sure but I think the cam chain is a bicycle chain type affair and I also
think you can install a new chain with a master link. This would eliminate the chain as a culprit.
The master link is NOT like the master link used on a drive chain. This guy needs have the plate
go over the pins and then you stake the ends of the pins (just like they do at the factory on an
endless chain) and are pretty safe to use. Some folks are put off by the master link chain but
I have never had a problem with one and have used a number of them over the years. Staking the
chain is a bit of a challenge when the head is on the bike as you will have to have some unwitting
assistant hold a backing as you have to whack the pins pretty hard using a punch.

If you are positive the current chain is the correct length, you can always find a stainless steel bolt
longer than the thing that is in your manual tensioner but I am guessing if its tensioning screw is not
long enough and the Suz manual tensioner are not long enough then the chain is likely stretched.
Not sure how you could install cam chain bumper bits and such wrong and if the bike runs OK then
the chain is obviously circling the bottom sprocket just fine. Anyway, let us know how this works out.

I roasted myself by thinking close to max wear limit was acceptable, usually I Usually go "if it's worn that much then replace it".

Yes I considered a linked chain but it was recommended not the way to go.

One of the first things I did was look down the cam chain valley to ensure it was on the bottom sprocket properly, and it was. It also appears there is no wY it could not be.

The bike fired instantly and revs just fine, just the light knocking, cam chain noise.

New Suzuki cam chain on its way, shocking it was only $105.00 Canadian!

 

[geol]

I hate to split the cases to install an endless cam chain and have used master link type quite a few times. The worst is pulling the engine but at least you shouldn't have to remove the top end. There isn't a way for the cam chain to have skipped off the crank sprocket if the bike started. If it had come off somehow, I am thinking the bike would turn over for a tiny bit with the starter and then you would have heard a loud noise.

Kawasaki Vulcans had issues with cam chain wear that was still within the service limit but the installed tensioner mechanism could not take up the slack. There was a part sold for the Canadian Kaw market that was actually the same tensioning device but had a longer throw and these things got VERY popular here in the States as owners discovered the problem could be fixed without yanking the engine and total disassembly. The Vulcan doesn't use the same type chain and a master link isn't possible.

 

[tom203]

"After playing with the tensioner tonight it functions perfectly. I did however figure out that when it is at its max outward travel it will free play "in" about .100". "

Not sure what this tensioner looks like, but could you add a tip to plunger's end to add some length so the ball stays on plunger's ramp to eliminate pushback?

 

[Fjbj40]

Sure that could be done. However, if the chain is stretched that much then I would assume if one was to do that then it would probably a short time before the chain failed.

When end I get the new chain I am going to do a detailed comparison to see how the "stretch" is made. For example is it the links that stretch? Highly unlikely, I think it comes from the rollers wearing down, which means those rollers will eventually fail. I saw a picture of a used chain compared to a new chain and that's what looked to be worn the most.

 

[one_civic]

If your chain was worn beyond spec, your timing marks would be slightly off but you stated that it runs fine and rev's freely. I would re-check the timing marks and see if they are slightly off, not 1 tooth off because that does not seem the case but even just a fraction of an inch. Sounds like you know what your doing.

just my 2 cents,

 

[Fjbj40]

Cams were dialed in 105/107. Timing is where I wanted it to be.

 

[geol]

"After playing with the tensioner tonight it functions perfectly. I did however figure out that when it is at its max outward travel it will free play "in" about .100". "

Not sure what this tensioner looks like, but could you add a tip to plunger's end to add some length so the ball stays on plunger's ramp to eliminate pushback?

The manual tensioner is basically a plate with bolt holes that align with the holes on the cylinder head and a threaded "bolt" that goes through it. To install, you just stick it in and tighten the two screws that retain the plate. Then you turn the bolt while observing the chain with the valve cover off and it is supposed to only deflect a certain amount.

It would be problematic to stick something on the end as the thing that was stuck on the end could come off. The more I think about it, if the chain is stretched to the point where more length is required to tension it, the chain may be at the point where it may fail and the chain should be replaced and looking for a way to tension it further than the original design may not be best.

 

[Steve]

When end I get the new chain I am going to do a detailed comparison to see how the "stretch" is made. For example is it the links that stretch? Highly unlikely, I think it comes from the rollers wearing down, which means those rollers will eventually fail. I saw a picture of a used chain compared to a new chain and that's what looked to be worn the most.

Just like the chain that goes to the rear wheel, the links do not stretch. It is the interface between the pins/rollers/links that gets worn. The ends of the pins wear down a bit, the rollers might wear a bit, the holes in the links get a bit larger. Any one of them is not much, but do that for over 100 links, it adds up quickly.

The cam chain will wear the same way, but it does have the advantage of somewhat constant lubrication and relative cleanliness going in its favor, so actual wear tends to be rather minimal. It is quite common for stock engines to have well over 100,000 miles on them and the cam chain will still be in-spec. Was your chain used with high-lift cams or have heavy-duty springs on the valves?

.

 

[Fjbj40]

Just like the chain that goes to the rear wheel, the links do not stretch. It is the interface between the pins/rollers/links that gets worn. The ends of the pins wear down a bit, the rollers might wear a bit, the holes in the links get a bit larger. Any one of them is not much, but do that for over 100 links, it adds up quickly.

The cam chain will wear the same way, but it does have the advantage of somewhat constant lubrication and relative cleanliness going in its favor, so actual wear tends to be rather minimal. It is quite common for stock engines to have well over 100,000 miles on them and the cam chain will still be in-spec. Was your chain used with high-lift cams or have heavy-duty springs on the valves?

.

The problem, I believe, came from the fact that the dreaded PO had removed it. And upon reinstallation did what a lot of us have found. The set screw was not released!

So how long was this bike driving around with the chain slapping madly and getting stretched even more because of the slack, tight, slack, tight cycles it was going through.

I paid $500 for the bike, I heard it running and that was it. It had a loud ticking noise from the top of #4 cylinder in the rocker area. Upon disassembly I found a flattened locating dowel for the rocker cover being mashed by #4 intake rocker arm. I figured that was the source of noise, until I started the disassembly of the engine.

 

[tom203]

" it would be problematic to stick something on the end as the thing that was stuck on the end could come off. "

A small cap spot welded on plunger end would be very secure- it's just pushing against the chain guide. Sure beats dismantling the engine now,cuz it's summer!

 

[Fjbj40]

" it would be problematic to stick something on the end as the thing that was stuck on the end could come off. "

A small cap spot welded on plunger end would be very secure- it's just pushing against the chain guide. Sure beats dismantling the engine now,cuz it's summer!

No hurry with this one, plus, I still have my 1000 to driventhego:

 

[Fjbj40]

So, new cam chain installed, cams reset, engine fired right up. Smooth and quiet, the way it should be.

So the old chain was still approx .040" shorter than the max of 157.8mm for 20 links as specified in the manual, the new one was approx .060" shorter than the old one.

So the old one was approx .600" longer than the new one, based on the fact the chain is 200 links long.

So when Suzuki says as long as 20 links is not over 157.8 mm you can reuse it, they are incorrect, IMOP. From this point fwd I will replace the cam chain, for $100, as a standard practice, unless it measures at least .060 shorter than the limit stated in the manual.

Sorry I am talking mm and inches, I did it all in mm during the inspection, just use to inches in my trade and is easier.

Cheers

I will try and load the pictures comparing the chain later today.