Topic: Adjusting cam tensioner with engine on? (Rattle noise)

[neurotoxin312]

So I've been having this rattling noise that I hear all the way up through about 6500 rpms. Sounds like it is the cam tensioner and when I took it to the mechanic he wasn't sure upon first sight/hear.

(1) I've tried adjusting it several time (correctly) and it didn't solve the problem.

(2) I thought that it could have been engine knocking and tried to also get gas with a higher octane with no avail.

(3) Spark plugs seem fine.

I haven't synced the carb as yet but I plan to do that along with valve adjustments and oil change this weekend. I also got a new rubber gas tank mount just in case it could be metal rubbing on metal there.

What I am asking is how safe is it to run the engine very low, while adjusting the cam chain tensioner VERY VERY gently to see is this makes the rattling noise go away? At least I would know that I could disregard other engine components this way.

[Tews19]

What bike are we talking about? 550? If so yes you can adjust while the bike is running

[neurotoxin312]

Yes I forgot to mention that it's a cb550. Really? You could adjust it with the bike running & and it is not risky in an way?

[mrbreeze]

I'd bet on the noise going away with a carb synch.

[CycleRanger]

I'd bet on the noise going away with a carb synch.

Yep.

[PeWe]

My CB750 user manual say that the tensioner should be adjusted during idle which is completely wrong.
It just become worse.
I guess that the design is different than CB550. I use the kicker and turn engine step by step with a pin inserted in the hole of the tensioner. I'll feel when it is in the inner position and lock the tensioner screw and nut there

[Duanob]

Use an angled flat blade screw driver and 10mm open end wrench. Turn the tensioner screw counterclock-wise to tighten the chain. But don't force anything just enough force to hold it while tightening the set nut. very small hands helps!  Do this first as it's part of the 3000 mile tune up. If that doesn't take the rattle out then do a vac sync since that would be the last thing you would do.

[neurotoxin312]

Just adjusted my cam chain tensioner yesterday while engine was running and this didn't seem to help the rattling noise, so I guess I could rule out the cam chain tensioner as the source of the rattling noise. Will be doing a carb sync later this week.

Here is a youtube video of the noise.

[mrbreeze]

You will be amazed at the difference!!

[neurotoxin312]

Are you still saying this noise is probably do to the unsynced carbs? Last time I checked (but didn't sync) only carb #2 was off xD

[mrbreeze]

If everything else in the tune up is good....yes.