Cam Chain Tensioner Parts Compatibility Question

[smg65]

For my peace of mind, I'd like to have a lock nut on my cam chain tensioner. Will the Type E lock nut and copper washer fit/work on my Type D tensioner (1976 XS650C) without modification? If so, other than finding the parts, are there any concerns?

Thanks!

 

[Brian902]

First thought would be the exposed threads would be too short because it was not designed for a lock nut.

My 78 does not have a locking nut and I've had no issues.

If the threads of the adjuster ever get damaged I would think that would cause some problems.

But if it's not broke don't fix it would be my view.

 

[smg65]

I suppose I've been influenced by many who feel that tightening the acorn nut will also turn in (and tighten) the adjuster. Actually, I have checked this, in a rather crude fashion, and have not seen any change in adjustment after tightening the acorn nut. What I did was to make sure all threads were clean and lubed, so the acorn nut would screw on with no effort, until the final tightening. I measured the position of the adjuster before and after installing the acorn nut a couple of times. I made a mark on the adjuster, and measured as closely as I possibly could to see if it had been moved. It was never tightened by the acorn nut. I suppose it could have tightened by a hair, but I couldn't see it.

Now this isn't to say that it never happens. I suppose if the parts don't screw together so effortlessly, the adjuster may tighten. What can i say... I'm a worrier!! One side of my brain says "you checked it out... it didn't move", and the other side says "OMG... what if you're wrong??!!"

You're right... it ain't broke... I shouldn't be worrying! Thanks, Brian

 

[retiredgentleman]

+1 to what Brian902 said. I have a 78 SE with no lock nut, and it never moves from where I set it.

So many bigger things in the world to worry about......................stock market crash, corrupt government officials, Russia/Ukraine war, Israel/Hamas war and Ebola, just to name a few

 

[smg65]

So many bigger things in the world to worry about......................stock market crash, corrupt government officials, Russia/Ukraine war, Israel/Hamas war and Ebola, just to name a few

Yikes! And here I was sitting enjoying an after work beer, and you go all heavy on me!!

LOL. You are absolutely right. My "problems" are indeed miniscule!

 

[XStretchified650]

I can only speak from my own experience. I put 18,000 miles on my 77 before parking it in 1989 and never had any trouble with the lack of a locknut. But now that is back on the road with a refreshed top end with a new cam chain and fresher guides, the lack of a locknut was causing problems.

Just theorizing....It makes sense that with the fresh and unstretched cam chain and new guides, less of the adjuster bolt gets screwed into the housing. It is possible that the cover threads are be meeting up with a greater number of threads of the adjustment bolt. There is enough friction to get the adjuster turning even though the cover threads are clean. Maybe the old spring has a little to do with it too.

I agree that there are bigger things to worry about, but this one had a solution. For $20 I was able to get a unit with a locknut and fix the problem. That is cheap peace of mind.

If I could fix that Ebola thing for twenty bucks I would do that too.

XStretchified

 

[5twins]

If you decide to do the upgrade, you will need the lock nut and the type "E" plunger. It is about 8mm longer than the type "D" plunger which lets the adjuster screw stick out more, and that provides the room for the lock nut.

 

[smg65]

Thank you all for the replies. While it's probably a matter of "don't fix what ain't broke" right now, they're cheap enough that it wouldn't hurt to have one at hand.... kind of like a "blue blankie" just in case. Meanwhile, I'll turn my attention to other matters. There's plenty to keep me occupied, although I'll leave the Ebola to the pros!