Author Topic: What have I got.  (Read 492 times)

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Paul miles

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What have I got.
« on: 07 June, 2017, 13:55:09 »
Hi guys
I'm new to the site but I'm in need of help. While doing a gas inspection in came across a bsa
And.. erm I haven't got a clue about what it is .age and so on. I'm not new to bikes  just British bikes I have never had one so pretty clueless  about this one
I have got engine and frame I'd just the need to know about this so I can get on with the task in hand
Any help would be much appreciated
Kind regards Paul

JulianS

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Re: What have I got.
« Reply #1 on: 07 June, 2017, 14:27:09 »
Post a photo and/or engine and frame numbers and someone will be able to help.

Or go to BSAOC website and research under "machine dating" tab.

Paul miles

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Re: What have I got.
« Reply #2 on: 07 June, 2017, 17:48:52 »
Frame number ZM20.4170
Engine gas a couple .near to the push rod tube . 10 9 54F
And on the crank case 66 . 1641 / 251
But no numbers at the Base of the barrel.

ANDY HIGHAM

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Re: What have I got.
« Reply #3 on: 07 June, 2017, 18:32:12 »
Frame number is a M20/M21. The number by the pushrod? tunnel is the date of manufacture of the engine. If the correct engine is fitted it would be a 500cc or 600cc side valve

JulianS

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Re: What have I got.
« Reply #4 on: 07 June, 2017, 18:44:08 »
I would say you have got a 1949 500cc M33 overhead valve.  Engine was shared with the 500 cc B33.

Basically designed as a sidecar bike.

The frame was also used for the 500cc M20 and  600cc M21 side valve engines.

I would have expected to find the engine number on the right hand side just beneath the cylinder joint. An M33 engine from 1949 would start ZM33

The 66 1641 sounds like  B31/B33/M33 crankcase casting number. So I suspect at least the crankcase has been replaced at some time in its life.

Below is from the 1949 catalogue.
« Last Edit: 07 June, 2017, 18:47:30 by JulianS »

Paul miles

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Re: What have I got.
« Reply #5 on: 07 June, 2017, 21:19:16 »
Thanks JulianS
Well I'm gonna go with you on this M33 500cc now the restoration will start
It's been in the celler since God was a boy and we are missing out quiet a lot of parts. We have the bulk . The crank cases are also shot with  crosion where it's been left on it left hand side it's just powder
There is absolutely no sign of any engine number so wonder if it was service replacement case assy but it's good to  see parts available for the old girl is still quite good.
We also
Have no log book or reg for it either  so I assume I will have to contact the relevant person in  aid to find out what it was so we can get a V5C logbook for when the time gets close for road worthyness

JulianS

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Re: What have I got.
« Reply #6 on: 08 June, 2017, 10:37:59 »
Follow the link to the BSAOC website for details of dating certificates registration etc.

http://www.bsaownersclub.co.uk/machine.html

You will need a complete assembled bike to apply for V5C rather than a box of parts.

Also se the DVLA site for info;

https://www.gov.uk/vehicle-registration/new-registrations