I bought a B31 engine today. It is almost complete, but I am going to strip it, rebuild it, then put it in my WM20. I fancy a bit more cruising speed and fuel range. And I think those engines look nice. I will keep the sidevalve to put back in should I ever want to.
I got it from Yeomans motorcycles at Bromsgrove. They are a nice bunch of blokes, made me a cup of tea and seemed very fair.
So expect pleas for more on line help from me in the future

email (option): gasboy@btinternet .com

Put one in my M20 for a while, made it a really nice bike. Gave me an impression of how good a B30 could have been.
Cheers, Mick.

email (option): mick@motorbikemike.org.uk

Mick
Why did you change it back to the sidevalver?

Does anybody know where I can download a workshop manual from?

email (option): gasboy@btinternet .com

Hi Peter

I have the parts lists and a few BSA service sheets on my site at

http://www.petercomley.com/partslists.htm

and

http://www.petercomley.com/BSA_Service_sheets.htm

if that is any use to you

Cheers
Pete

email (option): petercomley@web.de

I've also got a Haynes manual which you are welcome to. Always useful if you run out of toilet paper!
Cheers
Pete

email (option): petercomley@web.de

Originality!
Cheers, Mick.

email (option): mick@motorbikemike.org.uk

Hi Peter, Just as a point of interest..you will need an M33 head steady, B31/33/M33 exhaust system, an M33 petrol tank and the oiltank return pipe connections and a rocker feed pipe as well as the engine to do the changeover. Worth the effort though..a good (std) B31 will do about 70-75mph, cruise at around 55-60 and will always return mid 70s to the gallon.
And there is plenty of scope for power increases if you want them...Ian

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

Can you explain the reason for the M33 tank Ian? Is it just for the rocker feed fitting?

I thought you meant oil tank! I understand the petrol tank thing.

Pete C --- thanks for the links and kind offer of the manual. I am quessing you are in Germany as your email address ends de, so it will cost as much to post as if I buy one here.

Ian-- good point about the M33 head steady-- I would have obtained a B31 item. My tank has the cutaway bottom so I should be ok.

email (option): gasboy@btinternet .com

Hi Peter, the M33 head steady is longer than the B31 steady...hard to find, so you may have to make one. That's not too hard as it is just a tubular stay with the ends squashed down flat...Ian

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

Ian,

What do you think is a better sidecar puller? A B33 or a M21?

email (option): unpob@yahoo.com

The B33 without a doubt..8 bhp extra as standard (just over 50% more power), heavy enough flywheels and much better fuel consumption. Also much more scope for power increases.
I am currently building a 720cc B33 for a customer which is destined for sidecar duty.
My own B33 is a 720 and with an engine sprocket 4 teeth over standard it is still undergeared.
The torque is amazing..after only 1000 miles with the new engine I noticed it has broken a rear wheel spoke...That mayhave been a coincidence but the wheels have been fine for a long time!...Ian

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

You're gonna need one of them disk desert wheels for the Harley XA!

email (option): unpob@yahoo.com