Rotor removal

[MotoV4]

I couldn't find a string on this - though sure there must be one. Having charging problems and have now changed the battery, reg/rec and stator with new ones. Still stuck with a charge at 12.3 max at 3-4000 revs. Looking to swop the rotor now with a new one from Electrex. I dont have the "special tool" to hold the rotor in order to undo the bolt. Was wondering what others have used to get around this?

[MotoV4]

oops - Should have added that the bike is 82 J model

[london calling]

Use an air powered impact gun (wrench).

[martinz1000r]

or if no access to a compressor then you can get an electric version. Battery powered off eBay but expensive. I bought a Clarke Impact wrench which is mains electric for about £25. Also used it to remove sprocket nut. You can then hopefully use the rear wheel spindle to remove the rotor but if it is really stuck on you might need a special tool.

Also if using impact wrench make sure you have appropriate sockets. The wrench will just shatter standard sockets.

[Al]

I had a spell where the rotor just wouldnt stay on so made this up to hold it whilst tightening the centre bolt.

The shiny bit in the middle serves as an extractor to pull the rotor off whilst being held too.

The rear wheel spindle does fit but dont do what i did and use it as a slide hammer or you will crack the main bearing knock pins out of the crankcases and make them scrap.
The new ones from electrex come with a woddruff key slot because they are designed for several different bikes.
I have heard it said that in this particular application (112 ft lbs torque) forcing them up the taper can crack them along the keyway!!!!

I used mine with damaged (broken) magnets for about two years with no problems. It still charged the battery OK.
I just araldited the broken piece back in. Not recommended though. Are yours broken because if they arn't and you replace the rotor i would say that you may be wasting youre money.

AL

[Rich]

Check the wiring loom and earths before doing the rotor.

I have made one like Als' but mine is just welded up in a "C" shape with a handle out of 1" box section steel. Don't screw the bolts in too far or they will hit the magnets.

[MotoV4]

The rotor looks to be in decent shape but I had run out of parts to replace so went with the rotor. It doesnt have a woodruff key as you mentioned and had come off the crank last year, thats when the charging problem started. I assumed it had taken out the stator and started with that. It brought the charge up a little but still not right so swapped to a new rec/rec that I had laying in my spares. Same rate (12.4v), changed the battery and no joy so bought a rotor.

I will take the advice given on here and investigate further before I disturb the original rotor as it seems to be holding tight now and it may be best not to disturb it. If I do need to remove it I'll try the impact, I have one here and can borrow one from the farm if mine is not man enough. The tools you guys have made will give me an idea if I have to do that so thanks again.

[KeithZ1R]

Im with Rich here after recent events especially with respect to the earths high resistance on the ground wires / connections will cause low charging voltages

[PAULJAC47]

B4 you go any further on this, what are you getting between the 3 phase outputs from the genny? alternating current, and is it the same voltage between all three phases/usually the three yellow coming out of the genny/alternator....Paul J

[z1bman]

have you got battery voltage at the white wire to the regulator also 12 volts at the brown wire when the ignition is turned on

[MotoV4]

one of the 3 phases on the genny was lower than the other 2 which is why I suspected the stator (especially after the rotor had come loose on the crank). I havent checked the 3 phases since replacement nor the reading at the white wire.

I'll check both these at the weekend as the bike is still indoors and it doesnt go down well when I start it up to check readings, the smell seems to linger for a week or 2.

thanks for giving me these leads to follow, I'll let you know how they go, the riding season will be starting again soon here so I gotta get my finger out.

[Pigford]

I use a nylon tie-down strap to lock the rotor still - easy & cheap - worked every time for me & dose not harm the rotor.
You can wrap it round tight then tie it off to the foot peg or frame

[Keefleaf]

A friend had trouble getting his rotor off.good engineer,tried everything .
In the end it had to be destroyed to get it off.upon inspection it showed rotor had been loose/spinning and managed to heat weld itself to the crank!
" Steady as she goes ".