Hi All,
I need help! The B40 I bought last year is proving to be a bit (!) problematic.
Aside from the need for new crankcases (the replacements need work too) there are some smaller issues to be addressed.
First on the list is the clutch actuating lever. The one fitted looks to be the product of a home Worksop and doesn't fit quite right. Can anyone post a photo of theirs, possibly with dimensions? Thanks
There are plenty of pics on the web - just search BSA 40-3145: eg
https://www.bsaunitsingles.com/item.wws?cpubcode=BSA&sku=40-3145
Just looking at online pics, this one does look to be home made. The arm on the proper one has a rectangular cut out under the cup which this one does not. Also, the supporting pillar looks to be the wrong shape.
That said, as long as the dimensions are ok then this one may be ok. You should be able to check the dimension by screwing the lever into the inner timing cover and then checking the entry hole for the cable lines up with the inner cable hole in the arm, and that the cup aligns with the end of the clutch operating pushrod.
Thanks guys
The unit singles are all new to me.
The motor is in pieces at the moment but lining the arm up it looks a bit short. The pivot block is the worst part. The actual pivot bar was a cross-head screw with a bashed over end.
I'll start by making a new pivot block while I look out for a replacement arm.
The parts book shows a ball bearing in the cup where the rod goes, (what size is the ball?) is this just held in by the rod? If so I think the cup may need to be a bit deeper.
Thanks again.
The ball bearing 40-3071 is listed as 5/32" in diameter - from memory, I don't think it is captive inside the cup and, as long as the mechanism is adjusted to give minimum free play, there should be no way it can fall out.
Looking at a picture of the operating lever, the distance between the centre of the support pillar pivot on the lever arm and the centre of the cable jaw at the other end, is almost exactly 10 x the diameter of the threaded pillar. If the pillar is 5/16" thread, it would make the distance 3 1/8". If the pillar thread was 1/4", it would make the distance 2.5". Interesting to know what yours is?
Pivot to the cable end comes in at 2 5/8" so not too far out.
I'll set about trying to make up a new threaded pillar (1/4" cycle thread I believe), find a better pivot and deepen the ball bearing cup and see how it goes.
Unless someone has a spare they're happy to sell me?!
Thanks for all the help .
As you probably know, the early C15 engine is based on that from the Triumph Tiger Cub. The distance between the pivot pillar tapped hole in the Cub inner timing cover and the hole for the clutch cable is also 2 5/8". If the C15 is exactly the same then the operating lever (T1233) from the Cub might well be compatible and be an alternative part to look out for. It certainly looks to be the same in the Cub parts book.