transmission query

[red ghost]

Last time I looked at my insides (GP150) I noticed with the chain off, when I rotate the transmission the gear cluster and crown wheel spin in an eccentric fashion, is this a tell tail sign of of a worn gear cluster bush?

[red ghost]

bump...

[mark]

i had a new crownwheel that did this and it turned out the hole was off centre , this f@@ked my chain as well because there was a tight spot and a slack spot on every revolution.

[red ghost]

Is it a b@5t@rd job to change the inner bearing track?

And who would be the best one stop shop for inner/outer bearing tracks, bearings and a gearbox(Li150 or GP200)?

[red ghost]

bump...

[dapper]

If it is the inner bearing track for the cluster, the blind one in the casing, then find a local machinist and get a piece of bar turned down as per Sticky's manual (think it was exactly 22mm. from memory) and use Sticky's method of hydraulic extraction. Done it myself and was quite easy, but make sure you use plenty of heat on the casing as you don't want to hammer right through And better to use lots of light taps rather than heavy hits with yer hammer

[Muppet]

If it was the bearing track in the case why would it oscillate; wouldn't the slack in the bearing remain constant as the cluster rotated,

muppet,

[dapper]

The bearing track in the casing rarely wears. Was just recommending the way to replace it. More likely to be the bearing at the other end. It may be that the crown wheel doesn't have the hardened track and should have had the bronze bush instead of needle rollers, but you don't specifically say. I take it you have the shim under the crown wheel? Take the chain off and see how much slop there is when you rock the crown wheel against the spider.

[mark]

Like I said badly machined crown wheel

[red ghost]

I have two crown wheels, original Innocenti one and a ScootRS one, both do the same thing with bearings or bush fitted so I'm leaning towards the outer cluster bearing, hope that's the problem, bought a bearing today