dragonfly flywheel

[chippy]

Hi Everyone, Can someone please tell me if there is a runout tolerance to be checked when fitting the flywheel, if so what is it please.  Eric

[eddie]

Eric,
       Obviously, the truer the flywheel runs, the better. As a first step, try fitting the flywheel without the key to make sure it is seating on the taper and not riding on the key. If this gives an improvement, file a little off the top of the key, and try again. It is imperative that the drive should be taken by the taper - the key only makes sure the flywheel doesn't turn whilst tightening the nut. When you say 'runout', do you mean running out on the diameter or on the face? I would think 10 thou runout on the face would be tolerable but the diameter needs to be as true as possible to reduce vibration.

  Eddie.

[chippy]

Hi Eddie, Thanks for your reply, The flywheel that I fitted appears to be a in very good condition with no obvious, signs of overlapping in, or lumps or bumps on either tapers, I understand that the taper mating surfaces should be about 70% this was achieved with a small amount of lapping in. However I fitted the naked flywheel and checked the face with a DTI only to find a run out of about .018" therefore I suppose +or- .009" . a further check was to insert feeler gauges between the flywheel case (g/box mounting screw boss) in turn, adjacent to the 6 holes in the flywheel rim with a min max difference of .020" therefore +or- .010". I then borrowed another flywheel and did the same checks, results were, face +or- .0045"=.009" and rim .016" = +or- .008" ,checks carried out with key removed , keyways inline and nut nipped up.  Am I looking into this too much, or should I look for another flywheel. the one I borrowed appears to be within acceptable limits from your reply! Also is there a torque setting for the flywheel nut ?   Eric.

[Clive]

Hi Eric,
Before you rush out to buy another flywheel have you checked the shaft run out!!. i know it not supposed to be possible but how many times has the crank been apart best to start there and make sure the crank is true first. Put the crank between centres and check the main shafts .
Regards
Clive

[chippy]

Hi Clive, Thanks for your reply, I borrowed another flywheel and that seemed to cure most of the problem, so I,LL look for another flywheel locally.

     Eric