Author Topic: A65 Crankshaft  (Read 372 times)

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Mike Farmer

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A65 Crankshaft
« on: 02 August, 2017, 09:16:13 »
 :) :)
I have a barn find A65 that I think I shall rebuild.

Well what I actually have is a frame, swinging arm and bottom engine casings with only the gear cluster still in it (9bonus???).

My question is were the crankshafts standard and relatively interchangeable during the production of the marque. I can get a crank quite easily but don't want to end up with something that doesn't fit.

So as always your advice would be very much appreciated.

Oh almost forgot I've also got the rear brake rod (another bonus)

Mike ;D

JulianS

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Re: A65 Crankshaft
« Reply #1 on: 02 August, 2017, 12:58:00 »
There would appear to be some interchangability of crankshafts, but apart from the very early models the flywheel was different between A50 and A65.

The early flywheels lacked maching to take a timing peg. All pre 1965 took a ball main bearing on drive side.

All 1966 on took a roller bearing on drive side plus a different bush to take a thrust washer on timing side, they also had a cutout for the timing peg, and the later ones had a cylindrical timing peg.

Looking at the master parts price list from late 1970 BSA listed the OIF crank as a replacement for the 1966 on crank when stocks of the original were exhausted, but with the appropriate flywheel A50 or A65 and to match the timing peg I presume.

If it was me I would not put a pre 1966 crank in a post 1966 case and I would try to match the crank to the date of my cases.

Mike Farmer

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Re: A65 Crankshaft
« Reply #2 on: 02 August, 2017, 15:26:31 »
Hi thanks for that. I really had no idea as the situation has never been an issue
Since I read yours I contacted Draganfly to check if they had a good used one(they'll ley me know) and they said pretty much the same thing That they were all interchangeable except the A50 as you stated but you could end up with funnies like not being able to use the timing spigot/key. Etc
So we shall see.

Thanks again

Mike

Old Biker

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Re: A65 Crankshaft
« Reply #3 on: 04 August, 2017, 19:57:35 »
Hi, I have just read Julian S's reply about the crankshaft and have a question about the timing of the changes mentioned.

My A65 is 1965 (June build) but the crankshaft does have the slot for the timing peg, Julian's reply would seem to indicate that the slot was not there until 1966 always assuming this old biker correctly understood the reply.

Any clarification would be appreciated.

Cheers, Old Biker

JulianS

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Re: A65 Crankshaft
« Reply #4 on: 04 August, 2017, 20:19:23 »
I think your engine just missed the timing plug.

Photo below is from the A65 owners manual and shows the engine numbers from which the plug was fitted, they later chaned timing for the A65 and the plug was only to be used A50 up.

I think it came in around June/July 1965.

JulianS

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Re: A65 Crankshaft
« Reply #5 on: 04 August, 2017, 20:23:28 »
Mike

A bit more on crankshafts from 1964

Mike Farmer

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Re: A65 Crankshaft
« Reply #6 on: 04 August, 2017, 20:54:52 »
 :)

Thanks again for your knowledge. Draganfly have a few used ones in stock and I have purchased one from them. It is stil in standard configuration never been reground. Obviously as I'm trying to build a "new" engine I shall have that done. Got a pair of used bottom cases from Ebay. So we shall see.  And I'll scream here for help and advice. (and bits)

I'll let you know how it goes. As its a serious ground up rebuild I shall not keep it standard colour wise. But I;m not going to make a circus exhibit.

Thanks again

Mike 8) 8)

Old Biker

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Re: A65 Crankshaft
« Reply #7 on: 05 August, 2017, 10:57:10 »
Thanks for the knowledge Julian, the attachment showing the engine numbers from the point the timing slot was introduced indicates my engine was in fact one of the very first!

Thanks again from an appreciative old biker.

JulianS

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Re: A65 Crankshaft
« Reply #8 on: 05 August, 2017, 10:59:32 »
That is good news makes setting the timing so much easier.

christoff

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Re: A65 Crankshaft
« Reply #9 on: 08 August, 2017, 12:46:45 »
Hi all
Thanks to Bess and Julian for their information!
Now I need some clarification if possible,whilst rebuilding my 1963 A65 royal star, I am puzzled as to the fuel tank fixing I find that there are two methods of fixing the tank one as shown in the diagrams posted by Julian and a second way of fixing the tank is with the use of a large rubber bung in tne centre (as in the C15) I am probably mistaken in this but any help would be appreciated.
Yours Chris

christoff

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fuel tank fixing
« Reply #10 on: 08 August, 2017, 12:53:13 »
Hi all for some reason my question about the fuel tank fixing has now appeared under the question Mike franks has poasted re crankshaft?
cheers Chris