Good day!

I have had my newly purchased M20 at the repair shop for a second set of eyes on the problems before I strip it down for painting. One of the things that came up is that it is missing the sprocket that mates up to the magdyno pinion gear. It's not really too surprising as this motorcycle lived for ten years as a box of parts and the assembler was a hobbyist. Looking through the parts manual, I found the magdyno pinion gear number but cannot figure out the right mate for it.

Does any one have an idea on the description or part number for the right part?

Thanks for the help,
Justin

email (option): justininia@gmail.com

I guess you are looking for 66-2250 Magdyno idler gear.

Ron

email (option): ronpier@talk21.com

Your guess is certainly better than mine. :)

Thanks for the quick reply. Now off to the interwebs to try and find one...

Thanks again!

email (option): justininia@gmail.com

Hi Justin...If I understand you correctly you are missing the large gear that fits between the magneto drive gear and the inlet camshaft gear...

If so that is 'magneto drive idler pinion' and is part number 66-2250...Ian

email (option): ian@wright52.plus.com

Strange..

Why in some places it is referred to as 66-2251?...
(Magneto Idler Pinion, BSA B & M Group, 66-2251)

http://www.classicmotorcyclespares.com/index.php/default/magneto-idler-pinion-bsa.html#Default_Category

http://www.ebay.com/itm/BSA-Magneto-Idler-Pinion-66-2251-/130742634630?pt=UK_Motorcycle_Parts_13&hash=item1e70de4886

Noam.

email (option): noam10@gmail.com

My Air Ministry publication parts book lists it as 66-2250 Mag drive pinion with bush. Perhaps the fitted bush gives it another part number. I have found the same thing with the con rod. It is stamped with one digit different to the parts list. Probably again when the small end bush or big end bearing eye is fitted?

Ron

email (option): ronpier@talk21.com

Hi,yes as an assembly the number can change,gear and bush assembly listed on Russell motors at £30.00,I wish Les would up date his stock list,although I have seen posts where he has honoured the present prices,maybe that is the case.
cheers Rick

email (option): richardholt@rocketmail.com

Thanks Ron, Rick.

Yes, it makes sense!

Noam.

email (option): noam10@gmail.com

One on ebay now

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=181481057398&ssPageName=ADME:SS:SS:GB:1120