The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: Billybream on 24.02. 2020 15:02

Title: Primary Chaincase Level plug thread
Post by: Billybream on 24.02. 2020 15:02

Trying to find out thread of 15-645, it measures approx. 0.245", one of our threads lists states 5/16 x 26tpi but that's to large.
Can anyone advise, need to source one to replace stripped thread
Many thanks

Title: Re: Primary Chaincase Level plug thread
Post by: AdrianJ on 24.02. 2020 16:51

I would expect it to be 1/4" Whitworth.
On the plunger it's a 67-1711 BSW 1/4" x 1 5/8"  20tpi according to the wonderful A10 fasteners list from Steve Nott www.stevenott.com/bsatrinbw.htm
This is absolutely invaluable and it looks like his home page no longer works., so it's anybody's guess how long it will be around for.
Adrian

Title: Re: Primary Chaincase Level plug thread
Post by: A10 JWO on 24.02. 2020 18:14

I got new ones from Draganfly last year, they fitted fine if that helps.

Title: Re: Primary Chaincase Level plug thread
Post by: JulianS on 24.02. 2020 19:03

15 645 is a common 1/4 x 26 tpi cycle (BSF fits)