Removing rotor off the taper

[Joolstacho]

I'm replacing my alternator/starter clutch assembly (my charging is suss and the starter clutch is clattering - it's really sloppy -found my clattering noise).
I made up a slide hammer using a Honda front axle with the correct thread screwed into the rotor, and a dumbell (weightlifter's) weight, slammed out it pretty hard, tried boiling water over it too but no go.  Then I used a 3-leg gear puller - with the 12mm 1.5mm crankshaft bolt screwed in, but not fully - about 1-2mm from the face of the rotor -enough space to pull off the taper, tightened the puller and gave it a few sharp cracks. Still won't come off.
If the crank was out of the motor I'm sure the heatspanner would help but I'm reluctant to hit it with flame while there's oil all around in there. 
The rotor is already damaged so I'm not worried about damaging it more. I'd rather not have to buy an expensive special tool, (got an important ride -Island Classics, in a few days and it wouldn't come in time anyway)
Any other ideas?

[robfriedenberger]

Use a spacer like in the video, worked perfect for me!

[Joolstacho]

Thanks Rob, but I've got precisely the OPPOSITE problem. Adidasguy has a rotor that's loose on the crankshaft taper... mine is super-TIGHT on the taper. (been on there 25 years I'd guess). I'll try making up the spacer to do it, but it's that tight that I'm a little concerned about damaging the crankshaft thread or the nose of the crankshaft.
(BTW I note that Adidasguy makes the mistake of having a beer HALFWAY through the job... whereas real professionals make sure they're well primed BEFORE starting the job.    )

[adidasguy]

I have removed them from motors where they were not loose.
You must make the spacer from strong steel like an axle - not cheap Chinese home depot steel soft bolts.
The threads for the rotor are the same as a swing arm bolt. The only one on the bike that is the same. An extra swing arm bolt will work. Screw it in hard. It will come off.
Warming the rotor center so it expands may help.
It WILL come off. Being a press fit, the colder it is the tighter it will be.

[Joolstacho]

Yup. well I made 2 spacers, one that screwed into the crankshaft thread, and one 36mm 'loose' one like yours. Both are high tensile steel. I'm using an axle (good steel) off a Honda -same thread - to screw into the rotor.
Tried both and screwed in TIGHT (to the point that I reckon if I go any harder it'll strip the thread). I've given it a few judicious cracks with the 'ammer, and I've used a blowtorch to heat it.

Man, this thing is on MORE than tight!!! Won't budge.

The LAST thing I want to do is damage the crankshaft thread, -I do worry that the 'loose' spacer could tip slightly sideways under the pressure and do damage.
Anyway, I guess I'll try again tomorrow. 

[Joolstacho]

I know you'll all be relieved to know I've got the **stard off today! (I am!)
I made up a 12mm (same thread as the rotor bolt) stud 'spacer' 30mm long, with a screwdriver slot cut in the end to screw into the crankshaft, (which avoided potential damage to the crankshaft thread). It being threaded, I could adjust the depth that it protruded the right amount to contact the bolt I was using to screw into the rotor thread.

Now I should probably lap the taper with fine valve-grinding paste to ensure a good fit. In other taper fits similar to this I would usually give it a smart crack with a tube drift to bed it onto the taper before tightening, but I'd worry about magnetism issues and possible loosening of magnets so I won't do that.
I'm also wondering about a peen on the bolt flange after I torque it up to guard against the bolt loosening.

[robfriedenberger]

Pick up an impact wrench, you'll find other uses for it.

I used the 36mm spacer and the impact with my swing arm bolt and worked like a charm. I've done this on a few other bikes as well and the Impact is always the way to go forget about using a hammer it will only lead to damage and stress.

[sledge]

You need the proper gear 

Use one of these M16x1.5 R/H. Far stronger than the equivalent stock bolt and less chance off pulling out the female thread in the flywheel, put a smear of copper-slip or anti-seize paste on the threads



......and if you have got air, one of these.....



Never known it to take more than 10 secs.