Driven pulley rubbing on gearbox plate.

Finally getting around to putting my SP180 back together after a long rebuild so it has been a long time since I've had the clutch assembly on it and I just want to check I have it right because the driven pulley is rubbing against the gearbox plate.

It is a rolling nut engine but I also have a non-rolling nut 180 which I'm rebuilding. Just the make sure I've haven't mixed them up - rolling nut engine has roller bearing at back of driven pulley and non-rolling nut has the standard style flat bearing, right ???

I know the older non-rolling nut engine has a spacer between the gearbox plate and the driven pulley, but I thought the rolling nut engine just had the driven pulley hard up against the gearbox plate. When I spin the clutch assembly it is rubbing on the gearbox plate so it seems like there should be a spacer or something there. It is even making a visible rub line on the plate which has never been there before so something has to be wrong here.. any ideas??

 

have u got the spacer in the pully ? its behind the bearing and is just like a cylinder thats inbetween the bearings on the clutch its hard to explain but have a look and u will understand

 

Thanks for the reply mate. It's not anything to do with the driven pulley/clutch assembly I don't think, because it is the weld line on the back of the pulley that is rubbing on the gearbox plate. I haven't touched the roller bearing on the back. You would think a spacer between the driven pulley and the gearbox plate might stop it rubbing but I swear that these rolling nut engines don't have one but the older engines did. Would love for someone to clarify for me cause this is keeping me from getting the scoot back on the road.
Cheers.

 

im pretty sure they all should have a spacer inside has your one not got one inside you should hear/see it sliding inside it happend to my friends and the circle weld line was rubbing on the gear box cover so we noticed and replaced the whole unit for the one of a doner bike and it was fine no rubbing spinning free but this was a inner clutch nut but should be the same problem have a check and see if yours has the slide inside mate have u not got another clutch of another bike u can bung in there and try ?

 

Yeah your right it does not have a spacer inside the pulley like the old one does, but again I was pretty sure it was like this. How could the spacer inside the pulley stop the outside from rubbing? I can't get my head around it.

 

No others to try unfortunately only my two different style ones.

 

Now you have me thinking - I did change the bearing in it a while back... possible I could have left the spacer out I guess. Can anyone else confirm that the later ROLLING NUT engine has a spacer in the driven pulley assembly?

 

yeah thats whats happend you must have forgotton to put the spacer back inside and do u have a spacer i have 1 if u dont just cover postage and ill send it mate its deffo the spacer tho mate

 

Thanks a lot for the offer mate. I might take you up on it yet. I've been looking at some exploded diagrams of the driven pulley and I think the earlier non-rolling nut ones had a spacer but the later rolling nut ones didn't from what I can see. Does seem weird though unless it has something to do with the change in primary shaft design. Perhaps someone can confirm this?

 

I finally worked out what was going on if anyone is interested. I had previously taken the gearbox apart to change the hub bearing, and during reassembly it appears that I did not completely pull the primary shaft through the oil seal. I found this out when I put the clutch assembly on and then the transmission cover and put the nut on and tightened it. It pulled the shaft into place and the driven pulley no longer rubs on the gearbox plate. The shaft must have a slight taper which prevents the roller bearing from going past a certain point. There is no spacer behind the driven pulley on the rolling nut setup, only between the clutch bell and the transmission cover.