Removing Alternator Rotor

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Dec 27, 2005
I am in the process of fixing my primary chain i have had it off and replaced the chain and reassembled. I stared the bike and the clutch hub wobbles enough to see it cleary, i think it must be a dodgy spacer or shim behind the hub so i am in the process of removing it all again and am now ready to take the rotor off. How the hell do i do this without having to take the motor apart and put a steel rod infront of the conrods as described in the book, as this bike atm is pushing me over the edge and wants me to sell it. So please before i do something and regret it HELP ME PLEASE!!!!!
If the cranknut is off the rotor should slide off, you may need to use a puller to get it started. If you need to undo the cranknut then to stop the engine turning put it into 4th, and put the rear brake on, this will lock the engine and allow you to undo the cranknut.
Not sure how you got the old primary chain off and on without removing the rotor unless you have a split link primary? Never used one of those, mine were always endless but now have a belt drive. If you have the primary and clutch assembled and rear chain in place, put her in top gear and stand on the rear brake or adjust the brake so it's locked the drum. With a 2ft (or more) extension on the wrench a good fitting socket the nut should undo easy. The rotor might need easing off the crank with carefully placed levers. Don't lose the spacers between rotor and crank sprocket and the woodruff key.
The wobble you have from the clutch drum is well known, maybe you didn't notice it before? Mine does it and that's a newish aluminum belt drive part. Usually it's a bent mainshaft and unless it's really bad you can live with it or buy a new one. The shaft has no support beyond the outer sleeve gear bush and it's under quite a bit of stress. You should check the seating of the grooved clutch washer against the shaft circlip, that the circlip is in it's groove and in good nick etc. The clutch centre bearing cannot really be in other than square but check it's condition anyway.
Norton developed an outer support & bearing for the mainshaft in the 70's and I know SteveManey does one, see but you need a belt drive and modified inner case.
When i put the bike in gear it doesnt seem to lock the primary chain as this is how i torqued it up. could have i damaged the gearbox when i torqued the clutch hub up, last time i removed the rotor i just jarred the nut and it loosened as i gave the spanner one good jolt with a hammer. I am positive it will be a spacer as it wasnt a tight fit on the shaft and may have slipped out and is no longer centered behind the hub. I have the flue at the moment and hoping it will clear up soon enough to get out in the shed and fix it.
Sounds like the clutch center is not on the gearbox mainshaft splines correctly, you could feed some rope into the combustion chamber through the spark plug hole and use that to lock the engine.
the clutch has to be on the spline properly as the motor runs and i can see the primary chain spinning as i had the outter cover off, which is why i saw the wobble. Explain in more detail how rope is supposed to lock the engine???
To prevent your crankshaft from rotating as you torque or untorque the alternator nut, stuff a rag between the primary chain and the crankshaft or clutch sprocket.
With you piston down you feed the rope in leaving the tail outside, as the piston moves up it compresses the rope and stops the engine provided enough rope is in there, no damage to engine and when you reverse the piston you pull the rope back out.
Or hit it with an impact gun. You can buy an electric one if your air compressor isn't big enough.

The clutch would have to be hanging off the mainshaft by 1.25" for it not to drive the gearbox and wheel, the nut would not go on anyway. You have got the clutch assembled with plates and spring?? or could be your clutch is slipping badly? Can't imagine you've stripped any gears either.... Flu? it's summer over here or what passes for it!
Good luck and get well soon.
I used the rope idea and that was brilliant and the rag would work the same way. I am getting better day by day but our cold -2 mornings arnt helping to much.
Note with much interest on problem of rotor removal. I 'm not there but do not believe stuffing a rope into the cylinder is a very good idea (bent rods, valve tops etc. Low gear stop the rear wheel from turning put tork on a bar and correct socket. Also would not use a air impact wrench. This also transfers the impact on the internal moving parts..
Am only trying to help out . Have been at this for many years
Old Biker
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