Cam Chain Tensioner Preventative Maintenance

[herostar]

Hello everyone~!

My bike has been running pretty well lately and it's got me worried! I've done an overhaul of most of the systems on the bike since I bought it two years ago (electrical, tires, chain/sprockets, wheel bearings, brakes, cables, valve jobs, carbs) but I haven't done anything yet regarding the cam chain tensioner...

I would assume the bike still has the original tensioner, and that means it's 30 years old. The bike was ridden ~11k miles between '81 and '84, then sat until I purchased it. I have since put about 3,500 miles on it. At this point I have no real reason to think that it's bad, but I was wondering if there is a way I can test/check it and do a little preventative maintenance.

All suggestions are welcome! Thanks!

 

[DanTheMan]

I've never done anything to my timing chain tensioner except remove it when I replaced my head gasket, cleaned it up put a new gasket on it and it's worked fine for 90,400 miles. Probably nothing needs to be done with it.

 

[Guest]

Read up on the engine rebuild part of the Clymer manual and there's a method there for testing it.

Next time you do your valves, give it a go. Very easy check and worthwhile.

 

[koolaid_kid]

Here is an example of the rebuild process: http://bwringer.com/gs/camchaintens.html
I watched bwringer do it to my bike. The most difficult part seemed to be removing and installing the carbs, which should be a lot easier on a twin.

 

[herostar]

Alright, now that I've posted this up and said that everything looks good... the tensioner is leaking oil!!! WOO HOO!!

Soooo it looks like I'll be following bwringer's rebuild guide. It's just a small leak so I may not do it until I get a little more free time early this fall and I can keep riding it right now

 

[Guest]

Hahahahah I've never heard anyone get so excited about a tensior rebuild!

Seriously, it's nice and straight forward as long as your careful and do it right and absolutely don't forget to loctite the bits that need it, that's one thing you definitely don't want coming apart while riding!

 

[Charlie G]

I did mine without removing the carbs. It is possible with the right tools. Loctite or lock washer the nut that holds the knurled knob on the tensiner. Bad news if that nut comes off.

cg

 

[tom203]

Alright, now that I've posted this up and said that everything looks good... the tensioner is leaking oil!!! WOO HOO!!

Soooo it looks like I'll be following bwringer's rebuild guide. It's just a small leak so I may not do it until I get a little more free time early this fall and I can keep riding it right now

Don't forget to follow correct removal procedure for tensioner! loosen lock nut and Tighten lock screw on shaft before pulling it out. Once out, you will quickly see how it works.

 

[Steve]

While it's out, check the end of the rod for damage.

This is the tensioner from my wife's bike:

After a tender touch on the grinding wheel:

I dressed it a bit with a file before putting it back in.

With a dimple that size, it may not be able to move to take up slack, as necessary.

.

 

[Dogma]

...

With a dimple that size, it may not be able to move to take up slack, as necessary.

.

Wow. Any idea how that happened? Ordinarily there shouldn't be anywhere near enough force in the tensioner to leave a Brinnel mark like that.