Page 1 of 2

Flywheel refitting - help!

Posted: Sun May 04, 2014 2:53 pm
by Nerdy Norm
I've just fitted a new BGM stator, and I'm having a problem refitting my flywheel.

The woodruff key seems to be in correctly, but I can't get the flywheel to seat fully home. At least, I assume that's the case. It's sitting proud enough that I'm sure the fins would touch the cowl, and the nut only seems to be halfway down the threads (see pics) - is that correct?

I haven't torqued it yet, just tightened as much as I dare using a half-inch ratchet. The stupid thing is that I've had this flywheel off and on a couple of times with no problem until now...

Image

Image

Re: Flywheel refitting - help!

Posted: Sun May 04, 2014 6:16 pm
by wack 63
Cam centre too big for stator centre? Laminates too wide?

Re: Flywheel refitting - help!

Posted: Sun May 04, 2014 6:35 pm
by PeteB
It might sound bleedin' obvious, but the flywheel magnets haven't picked up a small nut or similar have they? Had something similar happen during my refit the other week. Probably best not to turn the flywheel until you're certain to avoid damage to coils/pick-up...

Re: Flywheel refitting - help!

Posted: Sun May 04, 2014 6:41 pm
by Nerdy Norm
Everything seems OK - the size of the BGM stator (the only thing I've changed) seems pretty much identical to the Indian one I removed.

I just wish that I'd taken a couple of photos before I removed the flywheel, as I'm now not sure if it's fitted correctly or not. It looks to me like the nut should screw further onto the crankshaft. Can someone confirm this?

There's definitely nothing stuck to the magnets, and I've even offered it up after removing the stator bolts, just in case that was restricting it.

Re: Flywheel refitting - help!

Posted: Sun May 04, 2014 6:51 pm
by PeteB
Does the flywheel "rock" on the taper, or is it seated properly? The flywheel definitely looks to be too far out from the mag flange, and the end of the taper not far enough through the nut. Does the flywheel turn ok after the nut is tightened a bit using just a wrench? If you've changed the stator, it may be worth checking that the wiring retaining clip hasn't twisted and bent over the stator wiring loom and is catching on the back of the flywheel (again, been there, done that...)

Re: Flywheel refitting - help!

Posted: Sun May 04, 2014 6:57 pm
by Nerdy Norm
It seems like it's solid on the taper, and it turns fine without catching the stator (which I guess it should if it's not far enough onto the taper). I've triple-checked the stator, it's definitely fitted correctly, including the retaining clip.

Re: Flywheel refitting - help!

Posted: Sun May 04, 2014 7:53 pm
by mick1
I agree it doesn't look right. For piece of mind (bit of a pain...but) remove stator and woodruff key. check stator fits in flywheel. If ok try flywheel on shaft with no woodruff key. Use this as your datum point and re-fit stator and woodruff key then flywheel.

Re: Flywheel refitting - help!

Posted: Sun May 04, 2014 8:08 pm
by Nerdy Norm
Thanks fellas - I'll do the "dry build" routine tomorrow.

Today's lesson: don't fit connectors on the wires before making sure the stator doesn't have to come off again!

Re: Flywheel refitting - help!

Posted: Sun May 04, 2014 8:22 pm
by PeteB
Good luck! I'm with Mick1 - the last thing to check is that the taper on the shaft mates with the taper in the flywheel, if it does check the woodruff key. One last thought: check the washer behind the flywheel nut hasn't gone "on the huh" (as we say hereabouts) and jammed the flywheel and taper solid...

Re: Flywheel refitting - help!

Posted: Sun May 04, 2014 8:35 pm
by Monty
Image
Just had a look at mine. Its a BGM stator as you have. Logic says if its hitting the stator it wont turn. I had the same last week when I was chasing wandering timing. I took the stator and keyway out. lapped in the faces with some valve grinding paste and measured the distance from the flywheel and housing. Rebuilt it and it was the same. My crank does seem to come out further than yours. Have you got a wavy washer and does your nut fit inside the flywheel down to the bottom of the recess. The old original nuts are too big for modern flywheels.
PS as mine is running like a dog what do I know.