Cam Chain Tensioner Looses Tension with Slight Pressure

[Guest]

I've read a lot of threads about cam chain tensioners.While I was performing a routine valve lash check,I noticed my cam chain had a little sag in it.So I pulled the tensioner plug, and turned the tensioner,to take the slack out of the cam chain.I checked the valve timing and it was spot on.I gave the cam chain a little push with my pointing finger and the chain sagged again.I looked down the engine and both cam guides are there and looked good.Is this the sign of a bad tensioner or something else?I've never had this happen on any motorcycle that I have worked on.

[JEEPRUSTY]

My chain also sags slightly when I push it.
You would need a pretty stiff finger to affect the tensioner.

What you are seeing is likely just the normal amount of play in the chain plus a wee bit of normal wear.

You can check the manual for the method of checking to see if your chain stretch is normal and also find the instruction for the tensioner as well.

[Steve]

So I pulled the tensioner plug, and turned the tensioner,to take the slack out of the cam chain.

I have no idea what you turned, because there is no "tensioner plug" that has to be pulled, then "turn the tensioner".

If you pull the tensioner off the cylinder block, you have to reset it to put it back in place. My money is on the probability that it has not been set correctly.

Before pulling anything off, try this: loosen the locknut on the tensioner, then try to tighten the set screw. I am guessing it's already tight. Loosen the set screw. If the tensioner moved, it was not set correctly. Tighten the set screw, then back it out 1/4 turn and lock it in place with the locknut.

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[ben2go]

I forget I need to be way more specific here.I have a GS500E.There is a small plug on the tensioner.Inside there is a screw.Turn it one way and it loosens and locks the tensioner.Turn it the other way and it unlocks and applies tension to the cam chain guide.When I mean sag,I don't mean a mm or two.I'm mean between 5mm and 10mm.That's way to much play for an engine with a 11,500 rpm redline.Most,if not all, of the other bikes I have worked on have maybe 1mm or 2mm.All of my other GS500E are the same,1mm or 2mm of cam chain slack.

[Steve]

I forget I need to be way more specific here.I have a GS500E.

May I suggest that you add it to your signature?

That would prevent erroneous information such as I just offered.

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[ben2go]

May I suggest that you add it to your signature?

That would prevent erroneous information such as I just offered.

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Thanks for trying to help.Doh....It was all my fault.I should have included the info in my first post.No harm no fowl.Sorry bout that.I'm off to update my sig line.

[ben2go]

P and possibly R post

OK, so after digging around and doing some investigative surgery,I found that my tensioner spring is really weak.I understand that this is a 23+ year old part.I can't afford $90+ for a new one at this time.So I am going to try winding the old spring a little tighter and try to make it till spring 13.That is if the world doesn't blow up on 12-21-12.

[Nessism]

I think you have the right idea. Just wind it tighter.

Ad for judging chain tension, you can't do this by checking the small section of chain between the cams. When the engine stops the spring pressure against the cam lobes may cause one or both cams to either turn toward each other, or visa versa. You can't know which so it's best to just ignore this. When the engine is running the chain tension will become more consistent.

Wind up the spring and make sure the plunger in the tensioner is pushing on the chain tensioner shoe. That's all you should have to do.