Sticky chain tensioner: your input welcomed

[zblip2]

Bought a used gs850g. It rides great and all. One thing though, the automatic chain tensioner's knob was stuck. It took a good deal of force to turn it counter clockwise. When it gave way, it was in a very sane manner (no grit or funny feelings), just like a screw that was in too tight. Once this was done, it was moving freely against the tension from the spring. It tends though to get stuck again (not as seriously) if I leave it alone for a couple of days. Is this normal for the camchain adjuster to have a tendency to get stuck like this?

Thanks!:?

[tkent02]

Is this normal for the camchain adjuster to have a tendency to get stuck like this?

Thanks!:?

Not normal, not good.
It could possibly cause huge problems in the engine if it doesn't do what it's intended to do.
Might be time to take it apart and see what's inside.
Pretty easy to do, there's a tutorial on this site someplace.
The hard part is reaching the mounting bolts.

[jimcor]

Thank Brian for this.

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

[mark]

My tensioner did this AFTER I rebuilt it. It was fine before. It works perfectly. I backed up the engine 1/2 turn to put the slack of the cam chain to the front of the motor, put on the tensioner and then turned the crank the proper direction, and the tensioner took up the slack perfectly, even though it sticks. I've heard some say its a problem, some say it isn't. I'm going to check it out again when I put my motor back together.

Just letting you know that you're not the only one with this problem.

[tomcat24551]

Bought a used gs850g. It rides great and all. One thing though, the automatic chain tensioner's knob was stuck. It took a good deal of force to turn it counter clockwise. When it gave way, it was in a very sane manner (no grit or funny feelings), just like a screw that was in too tight. Once this was done, it was moving freely against the tension from the spring. It tends though to get stuck again (not as seriously) if I leave it alone for a couple of days.

I have exactly the same problem on an '83 850. I have a theory as to what's causing the problem, but it is just a theory. I have not had a chance to really test a cure.

I took my tensioner apart and serviced it a year or two ago. The situation did not improve any at all. I am going to do it again when I get around to it, but in the meantime, you may find the following of some interest.

If you take the tensioner out and dismantle it, check the condition of the socket and ball at the end of the shaft that has the spring wound around it. You may find that the ball fits loosely in the socket and somehow doesn't want to spin easily. Then check the beveled end of the shaft that actually bears against the chain guide. Look carefully at the beveled end to see if there is an indentation where the ball has kinda dug into the end of the shaft. If so, I think you may be looking at the source of the problem.

I think that when that little ball gets sort of wedged in its socket, it becomes reluctant to turn and then the spring tension and the back pressure from the chain cause the ball to make a little indentation in the end of the shaft and pretty soon the tensioner unit just wants to stay in that place. Then it takes a major effort to turn the knob counter clockwise.

These were the conditions I observed in my unit. I don't know how to fix the ball and socket fit, but I did think about getting the end of the tensioner shaft hardened locally so that the ball wouldn't "dig" into it.

As I say, all of the above is just a theory. If the unit is assembled properly there is no reason it shouldn't turn freely counter-clockwise. Somehow, sometimes, the two shafts just seem to get wedged into place.

Interestingly, my '79's tensioner has worked perfectly for 27 years except for an oil leak. Its never been apart. The '83 tensioner leaks oil, too, so lack of lubrication ain't the problem!

Anyone have any other observations?

Tomcat

[mark]

I have exactly the same problem on an '83 850. I have a theory as to what's causing the problem, but it is just a theory. I have not had a chance to really test a cure.

I took my tensioner apart and serviced it a year or two ago. The situation did not improve any at all. I am going to do it again when I get around to it, but in the meantime, you may find the following of some interest.

If you take the tensioner out and dismantle it, check the condition of the socket and ball at the end of the shaft that has the spring wound around it. You may find that the ball fits loosely in the socket and somehow doesn't want to spin easily. Then check the beveled end of the shaft that actually bears against the chain guide. Look carefully at the beveled end to see if there is an indentation where the ball has kinda dug into the end of the shaft. If so, I think you may be looking at the source of the problem.

I think that when that little ball gets sort of wedged in its socket, it becomes reluctant to turn and then the spring tension and the back pressure from the chain cause the ball to make a little indentation in the end of the shaft and pretty soon the tensioner unit just wants to stay in that place. Then it takes a major effort to turn the knob counter clockwise.

These were the conditions I observed in my unit. I don't know how to fix the ball and socket fit, but I did think about getting the end of the tensioner shaft hardened locally so that the ball wouldn't "dig" into it.

As I say, all of the above is just a theory. If the unit is assembled properly there is no reason it shouldn't turn freely counter-clockwise. Somehow, sometimes, the two shafts just seem to get wedged into place.

Interestingly, my '79's tensioner has worked perfectly for 27 years except for an oil leak. Its never been apart. The '83 tensioner leaks oil, too, so lack of lubrication ain't the problem!

Anyone have any other observations?

Tomcat

That's interesting, I'll have to take my tensioner apart and check again. Thanks.

[zblip2]

I wish you would have sayd that it is normal...
Oh darn. I guess I'll have to bite the bullet and fix the thing. While at it, I'll clean the carbs cause they'll have to come off anyway to fix the tensionner.

Last spring, I voluntered to clean the carbs of a friend and some how, his bike stoped working correctly after that (oups).... I hope I don't do the same to mine.