Topic: 550 cam chain tensioner bolt

[marko59]

76 CB550: Hey, I'm putting the top end back together, cam is in, chain is on and the adjuster bolt/mechanism isn't operating as expected. When rotated clockwise, there is no counterclockwise return and the tensioner blade does not retract. It will rotate back and forth freely 30-45 degrees before resistance. The tensioner is extended and making contact with the chain. I can push the tensioner blade away from the chain and the bolt will jiggle a bit, no rotation noted. Naturally, I have no idea if the current tension is correct.

I'm not thinking I can remove the tensioner with out removing the head at least to examine it more closely. ?

I suppose I could button everything up as is and give it a go, but I'm ambivalent about that without some feedback.. Thoughts, suggestions and experiences are appreciated.

Mark

 

[Deltarider]

Does this help?

[Deltarider]

BTW, p.26 of the Clymer Manual is wrong in the part in italics under: Note. Where it says counterclockwise read clockwise and vice versa.

[bryanj]

You should NOT be trying to turn the sloted bolt, you have probaly pushed the rack and gear out of mesh and/or damoged the teeth.
You will have to remove head and lift barrels to remove the tensioner and hopefully repair or maybe replace.

The sloted screw is ONLY  for holding the bolt whilst you tighten the nut and MUST NOT be used to try an tension the chain!

[marko59]

Thanks for the replies. This is my first top end on new to me bike. Not sure if it was working properly to begin with or I damaged it when I followed the Honda manual recommendation upon disassembly to turn the bolt clockwise "fully" (approx. 90 degrees) and lock it down to loosen the chain.. I get how it should work normally. I'll pull it and go from there.

[bryanj]

Problem is it my be a lot less than 90 and any force does damage. Better way is with cam cover off use a finger to push slipper towards rear with nut loose then lock up nut.
You could try pulling the bolt outwards and see if you can feel it engaging with the rack.

What tends to happen is turning too hard makes the flat gear on the bolt(imagine a nail head with teeth) push the rack out of mesh and causing the crimped steel body to spring open allowing the "rack" to keep jumping out of mesh.

Hope that isnt too confusing for you

[marko59]

I get what you're saying, that's a good suggestion. I can tug on the nut while turning the bolt a tad and see what happens. 

[marko59]

Resolution. While pressing the bolt in it will mesh the gears, and turning clockwise retracts the slider. Let go and it self adjusts. If I go too far turning it will skip ahead like a stripped bolt. Start over. No tear down. A spare used eBay tensioner is on its way should I need it.

[bryanj]

Problem is it needs to stay "in mesh" with the nut tight. Sounds like you may have to take it out and recrimp the casing to hold the rack tighter, you will see what i mean when you get the used one!

[marko59]

What you are saying is that once the adjuster is "set", it is at its limit in terms of the slipper moving further away from the cam chain while still allowing "flex" to tension the chain forward during operation, hence. "automatic" tensioner, correct?

And if my pressing on the bolt engages the "gears" it needs to stay that way. Got it. Here's what I'll do first. I'll release the tensioner (cam cover is off) and set the bolt while pressing on it.. I'll press the slipper back with a thin screw driver and observe it and the exterior portion of the bolt for play. Again, as I understand it, setting the bolt should prevent much if any slipper movement to the rear. I'll observe for any movement of the slipper or bolt in that direction. I can also just tug on the bolt to see if it moves. I'll rotate the crank/cam also and observe.Go from there. (poor operating replication I know). Yeah still don't want to pull the head/lift cylinder yet...

On an other note, when I do replace the cam cover, how do I approximate the torque on all the screws? Should I just give them a rap with the hand impact driver. I don't want to replace them with allen heads.

I'm appreciating your feedback Sir.

[marko59]

I'm ending this topic. Thanks.