The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 1946-1950 => Topic started by: SixFingerJack on 12.11. 2017 10:30

Title: Primary chain tensioner
Post by: SixFingerJack on 12.11. 2017 10:30

Morning all,
I have a question about the primary chain tensioner.
As I'm rebuilding this motor from boxes, I have no terms of reference for several of the components.
The tensioner blade is secured to the crankcase by a spring steel plate, which is compressed by two nuts.
My question is, how much do I tighten the nuts?
Should the tensioner blade move freely, have some resistance, or be so tight that it will only move by use of the adjuster bolt?
Presently, I can move it by hand, but only with a fair amount of pressure.
 TIA

Title: Re: Primary chain tensioner
Post by: Greybeard on 12.11. 2017 11:11

Just loose enough for the adjuster bolt to move it. Possibly not loose enough to move it by hand.

Title: Re: Primary chain tensioner
Post by: SixFingerJack on 12.11. 2017 11:38

Thanks very much for the prompt reply, will adjust accordingly.

Title: Re: Primary chain tensioner
Post by: Greybeard on 12.11. 2017 11:43

The adjuster retaining bolts are wired on my engine.

Title: Re: Primary chain tensioner
Post by: SixFingerJack on 12.11. 2017 14:42

Thanks, I have locktited the studs in the crankcase, and lockwired the nuts to the studs also.
Although this is my first BSA, I already have an unhealthy obsession with thread locking devices and compounds due to previous experience with Harley Davidson's finest.