Cam tensioner maxed out?

[Guest]

83 850GLD. While working on my bike I decided to take off cam tensioner and make sure it was functioning properly, and it is. But then I noticed that it was at its max tension point. The bike only has 32,000mi on it (by odometer only). Should the chain even be at that point to max out tensioner at this mileage? I haven't measured the chain yet to see, but is it possible its a master link chain and the PO put it on with an extra link? And if it is how do I find the master link and remove it and install new chain without a motor tear down?

[tom203]

".......But then I noticed that it was at its max tension point. "

Just how did you arrive at this conclusion ? camcover off, drooping chain ? So tensioner plunger has run out of travel ? Did you "reset" it and reinstall correctly ?

[kjsamm]

".......But then I noticed that it was at its max tension point. "

Just how did you arrive at this conclusion ? camcover off, drooping chain ? So tensioner plunger has run out of travel ? Did you "reset" it and reinstall correctly ?

Yes cam cover is off.Pulled tensioner. Took it apart and cleaned it, reset it according to directions found in forum. Chain is tight, even with tensioner out chain was taut. Pulled chain a little with tensioner out and not much slack was obtained, but I may not have pulled hard enough to move cam chain tensioner guide to give more slack. Plunger on tensioner is all the way out. It is showing that there may be about 0.25mm left before tensioner is maxed, but obviously that will disappear once motor is ran. Meaning because plunger can no longer extend to put pressure on guide, so the only pressure the guide really gets is the tension from plunger spring. So when motor is ran the cam chain guide can move backwards allowing slack in chain.

[Nessism]

Sounds like your testing method is flawed. Measure chain elongation per the service manual and go from there. If the chain was flopping around in the engine there will be a lot of noise. GS cam chains routinely last more than 100,000 miles, or the life of the engine.

[Steve]

... I decided to take off cam tensioner and make sure it was functioning properly, and it is. But then I noticed that it was at its max tension point.

Unless you locked the setscrew before pulling the tensioner out, it will extend to the maximum when you pull it out.

Should the chain even be at that point to max out tensioner at this mileage?

Usually, no.

I haven't measured the chain yet to see, but is it possible its a master link chain and the PO put it on with an extra link?

If you had it apart, why didn't you measure the chain?

The stock chain does not have a master link. Rotate the crank while watching the chain to see if you see a master link.

Plunger on tensioner is all the way out. It is showing that there may be about 0.25mm left before tensioner is maxed, but obviously that will disappear once motor is ran.

How do you figure that? If the plunger is all the way out, how can there be another 0.25mm before tensioner is maxed? And what would make that disappear when the motor is run?

Meaning because plunger can no longer extend to put pressure on guide, so the only pressure the guide really gets is the tension from plunger spring. So when motor is ran the cam chain guide can move backwards allowing slack in chain.

What do you think pushes the plunger against the guide? The plunger spring. All the time, whether the plunger can extend or not. If the guide can move backwards, there is something wrong with your plunger, it should only be able to move out, unless you rotate the knob to release the mechanism.


Install the tensioner correctly, rotate the engine a bit then see if the upper run of the cam chain can be moved very much. You should see some deflection with modest pressure from your fingers, but nothing that could be taken as "slack".

.

[kjsamm]

Yep I'm confused now! 1.) Chain links are 21 on the (3) not 20? How do I fix that??????? 2.) Length of 20 links I got 150.xxmm well under the max of 157.80mm, so why is my tensioner at max?????

[kjsamm]

[QUOTE=Steve;2082503What do you think pushes the plunger against the guide? The plunger spring. All the time, whether the plunger can extend or not. If the guide can move backwards, there is something wrong with your plunger, it should only be able to move out, unless you rotate the knob to release the mechanism.


Install the tensioner correctly, rotate the engine a bit then see if the upper run of the cam chain can be moved very much. You should see some deflection with modest pressure from your fingers, but nothing that could be taken as "slack".

.[/QUOTE]
Tensioner is installed correctly, if plunger is extended all the way and does not compress the plunger spring fully like it should to keep pressure on guide, then there is play in the plunger allowing for guide to move backwards. Nothing wrong with auto tensioner or my install. Something else is wrong.

[tkent02]

The various engines have different lengths of plungers, but the tensioner looks the same on the outside. You sure you have the correct one for your engine?

[tom203]

Yep I'm confused now! :

From bwringers write up,some words of a advice ....take tensioner out and...

"Play with the mechanism until you grok how it works. That sounds vague, but it's easy to understand if you play with it, and very difficult to explain. If it helps, think of the tensioner as a mechanical one-way valve -- it can tighten the cam chain if needed, but it won't allow it to loosen. The pushrod can come out, but it can't go back in (unless you turn the knob.)"

There's a ball pushing on ramp (knob spring pushes on ball ) inside that prevents plunger pushback. Take a look

http://www.bwringer.com/gs/camchaintens.html

[kjsamm]

May have found problem, should you be able to see guide from the top? I can see it on ex side
http://rs1248.pbsrc.com/albums/hh492...=1404567528But not on Intake side

http://rs1248.pbsrc.com/albums/hh492/Kim_Gottfried/Mobile%20Uploads/cam2_zpsfc58e09b.jpg~320x480?t=1404567530

[Nessism]

You can not judge cam chain tension by looking at slack between the cams when the engine is not rotating. The cam lobes are likely to be skewed due to the angle of the lobes pressing up. When the engine is spinning the chain tension will be taken up by the plunger and all will be well.

Key things:

Play with the tensioner by winding up the spring and pushing in the plunger. Then release the plunger and watch it spring out. Make sure you have enough windings on the clock spring for the knob so there is tension pushing out even with the plunger all the way out.

Once you are confident there is enough tension in the clock spring, push in the plunger and wind the knob until the plunger is all the way in, then set the set screw snuggly. Install the tensioner assembly after verifying the cam timing is correct, and lastly release the tensioner set screw. You should hear the tensioner plunger shoot out with a click/clunk noise. Make sure the set screw is out at least 1/2 turn from where the plunger was released and set the lock nut. If all goes as planned you should be all set. Don't worry any further unless there is a lot of clattering noise from the chain. Of course all this presumes some idiot didn't monkey with the chain previously.

Good luck and hope this helps.

[kjsamm]

I'm not trying to be rude, but why does everybody keep assuming that I did not assemble the tensioner properly. It IS correctly assembled and functions properly. The problem is that it is at its max tension, but the chain falls way under max 20 pin length. So why maxed out? Also I think my timing has been advanced. When on (-) mark in pic it is correct but if I rotate so its on the (T) marking then according to where the 1 → on the cam would be, timing would be advanced. 1→ would then be facing diagonally down towards front tire. What mark does it need to be on? Getting mixed reviews. If it is advanced should I retard it back to normal? Still cant figure out why tensioner is maxed with everything else in spec??????

http://rs1248.pbsrc.com/albums/hh492/Kim_Gottfried/Mobile%20Uploads/P_20140705_100523_zpsf9f24200.jpg~320x480?t=1404572773

[Nessism]

The problem is that it is at its max tension, but the chain falls way under max 20 pin length.

What does this mean? As mentioned already, you can't judge cam chain tension with the engine stationary and looking at slack between the cams.

[kjsamm]

What length should my plunger be for tensioner? Maybe it is wrong size as tkent02 had mentioned

[kjsamm]

What does this mean? As mentioned already, you can't judge cam chain tension with the engine stationary and looking at slack between the cams.

The length between 20 pins can be no more than 157.80mm, mine are 150.38mm. Therefore my chain is fine. Not trying to be rude but please pay attention this time. NEVER had I said I was judging slack by looking between the cams. I am going by the tensioner its self. Which is at its max, but why with everything thing else in spec????
Proof its at its max, so please stop saying its not.

http://rs1248.pbsrc.com/albums/hh492/Kim_Gottfried/Mobile%20Uploads/P_20140705_103310_zps2fca2630.jpg~320x480?t=1404574381

As you can see it cannot rotate anymore.