Honda Xl250S cam chain sproket

[pmc57]

Does anyone know how an'81  XL250 cam chain sproket is fitted to the crank shaft, does it align on a spline, press fit, keyed or other? Also which way around is it supposed to fit??
Help appreciated.

[LWC82PE]

have you got a manual? it should show it in there.

[pmc57]

Yes I do, but it does not give any detail on how it's fitted. It just goes into alignment with the location pin used for the advance mechanism location. My  concern is the sproket itself is has a boss either side, with one side one side being longer than the other. As is, the sproket is fitted with the narrowest boss closest to the main bearing. However it seems thet the cam chain has been contacting with the washer fitted between the main bearing and the sproket, this tells me the sproket may have been fitted the wrong way around. Although I haven't given too much effort into it, the sproket does not want to move easily, hence the request for advise before I get too carried away.

[matcho mick]

most honda singles bottom sprockets (circa up - 80's)are shrink fit,heat n drop,(and heat for removal too) just don't cook the main!!,& from memory( ),theres no indexing,just line any tooth up vertical,can't remember which way long/short shouldered spacer goes,obviously if it's fouling fitted short,fit it the other way?, hth!,mick