cam chain slack

[Guest]

Hello GS collective,

1982 GS1100 gk owner here. Have a bike that I got running after sitting for about 1.5 years. Started it 8 or 10 times while still ironing out the kinks when one day I hit the starter and it went "KATHUNK" and then the bike was basically locked up. From some advice I got on here, seems like it was the cam chain. From what I can tell the chain was maybe loose and would kink and bind up at the crank.

I re-timed it, zeroed out the tensioner and reassembled everything and now it turns over, but my concern is the amount of slack in the cam chain and I'm afraid it will want to jump a cog. (See pic above - sorry it's sideways).

MOST of the cycle it is pretty taut, but then there is one "sweet spot" where it gets lax. What I THINK is happening is that the valve springs on the cams want to put one cam one way and the other cam the other way and then it gets loose in between. I understand that if the tensioner were keeping the chain absolutely tight, then there wouldn't be enough slack for the cams to roll, but I think maybe the valve springs are basically stronger than the chain tensioner.

Questions:
1. Does this seem like too much slack in the picture?
2. Is it normal for the chain to get loose-tight-loose through one engine cycle?
3. Would a manual cam chain tensioner solve my problem? (feel free to interject any overall opinions on manual versus automatic cam chain tensioner).

thanks.

[tkent02]

1. Yes
2. No
3. Why not see if your cam chain tensioner is working. A lot of clueless POs don't loosen the screw before locking it down, thinking they are "adjusting" it or some such BS.

[chuck hahn]

No slack in the chain...ever!! Your tensioner needs attention. The push rod is stuck. Loosen the 13 MM jam nut and back off the adjuster screw first off to see if the PO had it locked down. Do this before anything else. Proper adjustment procedure is to turn the adjuster screw in till it hits the push rod. Then back out 1/4 turn and set the jam nut. Its not really an adjuster per say..its more of a guide so the rod doesn't have side to side play when working.

[Chopperjake]

thanks for the quick replies.

I don't THINK my pushrod is stuck. I've had the effing thing off and on 10 times while messing with this. If I turn that knurled knob counter-clockwise, I can put the rod all the way back in. Then I lock down the slotted screw. I install it the tensioner with 2 10mm bolts. I release said slotted screw (once at least I clearly heard the "crack" of it springing). I then turn slotted screw IN all the way, back it out 1/2 a turn, and while holding it there I tighten the locking nut. Done it ten times probably, but STILL get some lag in the chain.

Only 1 question this time:
1. WTF?

[chuck hahn]

well if youre getting some tention after releasing it from a retracted position, I would take a look at possible guides being worn real thin or broke. Stretch is one thing but that picture is way too loose to be "normal" stretch in my opinion.

[Chopperjake]

picture 1....

[Chopperjake]

picture 2....

[Chopperjake]

picture 3...

[Chopperjake]

picture 4...

[Chopperjake]

Picture 5.

(sorry to be obnoxious - couldn't figure out how to get all the pictures in same post).

See in the first 2 pics how my "external" spring is boogered up around the middle? I think a few "turns" of the spring are inside the crease there and it doesn't allow the knurled nobby thing to return all the way home.

In picture 3 is the "untouched" pic of the tensioner. Pic 4 I am pressing it in "a little" without having to turn knurled knobby thing and it only takes a small to medium amount of pressure.

Pic 5 is after turning the knobby thing, and I need a grip like the terminator to hold that spring down like that.

So, is my problem that my tensioner isn't "strong" enough to hold the tension out at the end of its travel path because that "outer" spring guy can't close all the way and I need that outer spring guy working in order to have that "high tension" pressure at the end of it?

(thanks so much for the help by the way).

[Chopperjake]

sorry, forgot pic 5...

[tom203]

I think your knurled knob spring is past its due date. Basically, that spring setup pushes on ball/ramp gizmo that lets plunger feed out, but jams up on pushback. Here's a similar unit

[Chopperjake]

awesome. thanks for reply. just ordered a replacement on ebay for 11 bucks - supposed to be here by monday.

is there any reason to go manual tensioner instead? (guess I could search the forum before asking a redundant question....)

[1948man]

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

Some general info here. I think general consensus is stick with OEM tensioner although manual is okay.

[Chopperjake]

Just some follow-up. Got the new cam chain tensioner. Definitely can tell that its spring action feels "solid" throughout its travel - unlike my old one that was soft on the last 1/2 inch or so.

Twisted and locked the new tensioner, installed it, unlocked it (definitely it "clicked" into place) and then I turned the engine through a few cycles. No more locking or binding up. Now the chain seems to be as tight as a ...... well, seems pretty tight.

thanks for everyone's help.