85 GS550 Cam Chain adjuster

[tomshell]

My recently aquired bike now seems to run half way well. Cleaned carbs,replaced air filter,fixed leaking(stripped) oil drain bolt,and attempted to adjust chain tensioner. Removed the tensioner, cleaned per instructions found on this site,and reinstalled. Top end still noisy. Took back out and noticed it is not extending all the way when in the motor.Repeated several times. Removed it again and forced the plunger out, tightened set screw to hold it extended, and installed using the bolts to draw it in. Top end quiet now, but ide is erratic and it seems the timing may have jumped with all the monkeying around I did.Anyways, I saw reference to an aftermarket tensioner on this site but can not find it now. Anyone point me to it? The stock tensioner seems to be hosed and I am sick of removing and reinstalling it. Thanks.....Tom

[Steve]

Your tensioner is probably good. From your description, I would suspect your installation technique.

If you look at the tensioner plunger, you will see a notch in one side. When you retract the tensioner for installation, that notch will go past the set screw so the screw will lock down on the round part of the plunger. VERIFY YOUR CAM TIMING BEFORE PROCEDING. Install the tensioner, loosen the set screw (it should take less than half a turn to loosen it). Rotate the engine (by hand) about half a turn to make sure all the tension is taken up on the proper side of the cam chain. Watch the knob on the right side of the tensioner to see that it moves while the tensioner is compensating. Now turn the set screw in several turns until it bottoms out (it goes farther because it will be in that notch), but also bring it back out about a full turn, then lock it in place with the lock nut. This assures that the plunger will not be able to escape if the cam chain breaks, but it also allows movement to take up any slack.

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[tomshell]

Your tensioner is probably good. From your description, I would suspect your installation technique.

If you look at the tensioner plunger, you will see a notch in one side. When you retract the tensioner for installation, that notch will go past the set screw so the screw will lock down on the round part of the plunger. VERIFY YOUR CAM TIMING BEFORE PROCEDING. Install the tensioner, loosen the set screw (it should take less than half a turn to loosen it). Rotate the engine (by hand) about half a turn to make sure all the tension is taken up on the proper side of the cam chain. Watch the knob on the right side of the tensioner to see that it moves while the tensioner is compensating. Now turn the set screw in several turns until it bottoms out (it goes farther because it will be in that notch), but also bring it back out about a full turn, then lock it in place with the lock nut. This assures that the plunger will not be able to escape if the cam chain breaks, but it also allows movement to take up any slack.

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I did not rotate the motor after releasing the set screw. That makes sense and I wish I had thought of that. Part of the hassle with this is the top bolt that holds the tensioner on is broken off in the block. The po decided to then drill and tap an additional mounting hole beneath the original, and it is a real b*tch to get to. Anyways, I guess I will remove the carbs, verify the timing,attempt to remove the broken stud, and reinstall the tensioner. Do you have any info on the after market tensioer? Does it work better? I want to get this done and quit having to mess with it....forever....

[tomshell]

Thinking more about this, I do not understand why the tensioner would not work correctly even if I did not rotate the motor by hand, effictively taking up the chain slack so to speak. After the jamb nut is tightened, the tensioner plunger is still free to move in(tighter) by itself and is driven by the spring force right? So why would the method i used be any different from the one Steve suggetsed....I am confused