What are the thoughts on the kickstart pinion bush?
It's this soft little bush that holds the clutch in place.
Tighten the nuts too much and the bush swells resulting in a sized pinion gear possibly wrecking the mainshaft too.
Also then important is the two nuts and the lock tab. Ultimately, it's these three items doing all the work.
24-4282 Nut, 24-4278 Lock washer, 24-4255 lock nut.

I've made a few bushes, some in PB1 bronze and also in an Oilite material.
Oilite is a sintered bronze impregnated with oil. Much softer than PB1.

As the kickstart assembly basically runs dry it makes more sense to use grease rather than oil. So, the Oilite will hold the grease better than PB1. The cost being it's more fragile.



Mark

email (option): pes.sales@btconnect.com

I've never seen a seized pinion bush, rather they are generally worn on the outer surface...For that reason I wouldn't be inclined to use an even softer material personally...
The whole point of the nut, locknut and tab is to set the assembly so there isn't excessive axial load caused by overtightening...This is covered in the BSA factory worksheet N0. 608 where it is noted that the nut should be done up no more than hand tight before fitting the tab washer and locknut...I generally set it up so there is a couple of thou end float, just perceptible after tightening the locknut...
Oil is usually present when the parts are stripped down so I'm not sure about the level of lubrication it gets...The bearing is low enough in the gearbox to pick up the oil that passes through the hole in the inner cover and that may well end up finding its way to the bush...As the bush has an oil scroll machined into it I'd have thought BSA expected some oil to get there...It's certainly not dry in the outer cover as witnessed by the oil leaks that can occur at the kicktart quadrant bush and both ends of the gearchange shaft...Ian

email (option): ian@wright52.plus.com

Yes, some bushes are quite worn, which surprises me as they are hardly 'in function'. It makes me wonder...could it also be deformation of the bush caused by the pressure of hard kickstarting?

BR, Michiel

Which is probably exaggerated when the valve lifter is not used correctly. It surprises me how often I see the valve lifter is not understood or just not used at all! Ron

email (option): ronpier@talk21.com

It's odd that on the unit singles it's a hardened and ground steel spacer/bush. It you use a tab washer it will collapse, and the nut loosens.
Gluing the nut is the only viable solution. This is for extreme racing though. Holding the kickstart down whilst riding will cause it to weld to the pinion gear and mainshaft. Race over!

This was another of my worries that the side loading whilst kickstarting could deform the bush if it was made from sintered bronze.
I'm feeling that's it's service life would be better using PB1.

Also, it's worth remembering that bad gear changes can subject it to extra forces. Any free play when fitting it would be a mistake, along with crushing it.

Mark

email (option): pes.sales@btconnect.com

If the standard bronze bush really deforms under hard and long kickstart pressure it could also make the pinion to tilt a bit under pressure and might be one of the reasons for the often skew/oblique/slanting?? wear of the pinion teeth and kickstartquadrant.

With a steel bush you can also safely clamp the whole mainshaft assembly with all its bushes and shims firmly around the small bearing without worrying to deform it. BR Michiel

I'm not overwhelmed with the tooth profile on the kickstart gears and that may not help with the loading Michiel.
Before I made any steel bushes to retail for the pinion, I would test them extensively myself. But it does make more sense to have a steel bush that you can tighten against without fear. Sorry for my Blasphemy.

The kickstart gears will have to be sent away for the profiles to be analyzed. The result I expect will be that the gears I produce will not be compatible with the Indian ones in use now. One good thing will be that my kickstart quadrants will be supported by the layshaft bush.

Mark

email (option): pes.sales@btconnect.com