Hi I have a 1942 bsa m20 and was wondering what weight oil I should use and the appropriate transmission fluid I should use. The manual says 50 weight for the oil but after doing some research I found the oil has changed a lot since the 40 ' and was wondering if anyone could tell me what works best. I also would like to know the appropriate transmission fluid to use as well. Thank You

Hi Barrett,

Oil tank capacity 5 pints 2.8 liter
Gearbox capacity 1 pint 0.6 liter

http://www.wdbsa.nl/useful_data.htm

The oils should basically be 50 both for engine and gear.
Gear must not be synthetic oil, as it eats up the bronze bushings.

This is the basic.
The oil subject had been discussed here many times, with a lot of pros and cons
For every type and viscosity...

Noam.

email (option): noam10@gmail.com

Hi Barrett, you need to read the other post on the forum about oils.

http://pub37.bravenet.com/forum/static/show.php?usernum=3155626639&frmid=16&msgid=1325496&cmd=show

email (option): horror@blueyonder.co.uk

You won't go far wrong with an SAE 40 for engine, gearbox and primary chaincase...it's worked for me for around 40 years using my BSA singles as my main form of transport....

Saying that though, I have also run quality 20/50W multigrades on numerous different occasions without problems, so I would consider that a sensible alternative...

I would say avoid any lighter multigrades such as 15/40W etc. and don't use hypoid gearbox oils at all in the gearbox...These types can damage the bronze bushes...

You may be as confused as you were to start off with after you have read all the posts and articles.. ..However, the above recommendations do work.....Ian

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