AJS & Matchless Owners Club

1965 G2csr

Hi guys

just a quick one..can someone tell me the size of the primary chaincase drain plug please

ta

In the bottom of the primary cover? - 1/4 Cycle.

Thanks M... I thought so but couldn't get 1/4BSC to screw in- the thread must be damaged -Didn't want to put the wrong tap through it to clean it up

cheers

The plug in three LWT primary chaincases in my possession are 5/16 BSF (22TPI). Is 1/4 BSF (26TPI) the original size?

Something I remember from way back is although both 1/4 bsf and cycle are same tpi but not thread angle. I can hear my dad saying “just wait a minute” while I spannered it in claiming”it fits”.
Easy to convince yourself especially straight into aluminium.

You're right but the difference scarcely matters in practice for 1/4 size.