Hi I posted a question awhile back about a carb spacer but received advice on a gasket. I have seen other m20's being restored and have heard on this forum of putting a spacer between the carb and the engine. It looks around 1 to 1 1/2 inch's and is sold in draganfly and believe is aluminum. I have read that the motor runs better with this adapter. Any advice or info because I just rebuilt the carb and am lwould like to kknow what works the best for this motor. 1942 BSA WD M20

The long aluminium spacer was fitted to the post war M21's and possibly M20's of the '50's. It can be used to good effect on the WD models but would not be period correct.

I have such a spacer on my M21 with a fairly thick insulating "spacer" as well. This allows the monobloc I have fitted to clear the magdyno. I recently measured the temperature of the motor after a good long run and found the cylinder head to be 170°C (max close to the exhaust valve and engine fitted with a copper head gasket) while the carb body was at 40°C just a couple of inches away. Not bad those insulators!

Cheers
Pete

email (option): petercomley@web.de

I use a 1/4" thick 'Tufnol' spacer to good effect on the WD bikes with a paper gasket either side of it to ensure a good seal..As mentioned the aluminium spacer isn't correct for the wartime period if that is a consideration...It also isn't absolutely necessary as part of insulating the carb from cylinder heat either...Ian

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

I got my Tufnol spacer from www.canddautos.co.uk and I simply measured the aluminium one that was on there and they made one to suit. That way I didn't have to replace the studs.
With a refurbed mag and a Tufnol spacer, hot starting is much easier than it used to be.