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A65 Primary chain tensioner #748792 09/11/18 6:45 pm
Joined: Dec 2017
Posts: 211
F
ferretjuggler Offline OP
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This is something else missing from the pile of bits that will eventually become my '72 A65T

Apparently there are two types, the later type 70-8310 being the part that I need.
Apparently this later version is interchangeable with the earlier type - so what exactly is the difference please ?

And just to confuse things, there are some "funny looking" tensioners that have appeared on eBay lately.
The rubber pad is shorter than the original and stuck at the end oppersite the pivot hole.
Are these any use at all ?
Or are they just a part off a completely different vehicle (like a cam chain tensioner blade) that just happens to fit ?

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Re: A65 Primary chain tensioner [Re: ferretjuggler] #748835 09/12/18 2:20 am
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Mark Z Offline
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The earlier tensioner is shorter, and receives a cap on the outside end, to keep oil from leaking out around the tensioner bolt. Also, the cup that receives the fiber "puck" is a separate piece, which is pinned into the tensioner bolt.

The later tensioner is longer, is all one piece, and receives only a locknut on the outside (which, with a fiber washer under it, serves to keep the oil inside equally well).

The earlier tensioner gives you less leeway for adjustment, which can be looked at as a bad thing or a good thing. Once the bolt is turned in so far, there's precious little thread left on the outside to get the oil cap on. If one or two coils of thread get worn down at the end, you start having trouble getting the cap to stay on. The newer type tensioner has plenty of thread sticking out of the case, not having to accommodate an oil cap. I've converted my bitsa to the later type tensioner.


Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: A65 Primary chain tensioner [Re: ferretjuggler] #748837 09/12/18 2:32 am
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Mark Z Offline
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Sorry FJ, misread your post, I thought you were talking about the tensioner BOLT.

Don't know what you're looking at on fleabay, but I have a few used tensioners lying about, presumably from '65-'67 engines, and they're all the same. I don't know what would have changed in the primary in '71 to require a different tensioner.


Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: A65 Primary chain tensioner [Re: Mark Z] #749157 09/14/18 3:54 pm
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ferretjuggler Offline OP
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Just bought a new tensioner blade on fleabay.
It's the correct shape but apparently it is both part numbers at the same time.
ie 70-8310 and 68-0244
I'm not sure exactly what the difference is between these two blades, but I've got a feeling that I'm about to find out.
Apparently it's British made but MCA brand.
Fingers crossed that it's not cheap tat.

The tensioner bolt will be the next thing to sort out.

Re: A65 Primary chain tensioner [Re: ferretjuggler] #749237 09/15/18 3:16 am
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Mark Z Offline
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I'm still betting that there's no change to the tensioner blade - hope I'm right.

In regard to the bolt, see my first post. Just insert the word "bolt" after every instance of "tensioner".



Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.

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