bronze in filter

[G-Man]

I think it could be much more durable. I'll check my spare '61 engine to see what that has in it.

G

That's a design I've never seen. ..............lm

The bush in my 1961 engine has a much larger, tapered flange in the middle, no oil hole and a straight oil groove. It doesn't seem to have suffered any wear, despite the 350 kit in the engine.



The kickstart gear has a matching large taper which mates up with the bush.



I wonder why they 'improved' the design?



I suppose the straight slot and the taper were extra machining operations and the 'new' style could all be made quickly on a single setting in a lathe........

Looking at the fit of the early bush in the gear it is clear that the adjacent part cannot put any load on that flange because it is below th esurface of the kickstart gear. Interesting. I've not looked at a later gearbox for a while. Must go and look. Perhaps it's possible to come up with a better bush.....


G

my thinking is if the radial clearances are tolerable---use it. don't worry about the ridge/flange.
Good luck
Randy

[border0_3]

Hi Graham,

On checking many of the gears in this installation , they all seem to have that chamfer.
Certainly the chamfer on the gear and a normal bush gives minimal surface area for the bush. Faster wear.

We have had some bushes manufactured, not with the chamfer to match the gear but a slightly larger diameter of the centre lip (more surface area to spread the load)

Regards to all Richard

[OldStan]

Did some more looking at my gears. Transmission in this bike are the last issue, shallow splines on the shafts. The first gear has almost no taper. When I replaced the bushing it was because the shoulder was so small, now looking at it, it's a match for the small taper on the gear. I have a gear from a slightly older transmission and it has more taper and a bushing that matches that. I think I'm going back with the original gear and original bushing which fits properly in the other regards. Guess I should have done that in the first place. With so little taper in the gear the aftermarket bushing must have been binding, or at least that's my guess.