Flywheel Disintegration Cause.

[LostanFounds]

Hi, Back on the wagon..!
I own a HRC kitted VFR400R NC30 (89 model)
I intend to give it some trackday action so wanted to make more competitive without breaking the bank.
Will be putting on some mods as per the really useful advice section on the site... (Fantastic...!)
So far all I have done is clean/check carbs, clean/check cams&valves and add a new Li-ion battery.
Upon purchase the engine was standard (I'm told - and looks it..) with suspension mods to take my 13.5st.
However, upon a recent fire up I discovered an unpleasant noise and the bike locked up...!
Upon a strip down(should've done this first, I know...)The flywheel inners have disintegrated.
Can't for the life of me think why..?
Is it the age of the bike.?
Is it the New li-ion battery.?
Seeing if anyone has ever had this issue and could provide a diagnosis before my solution of fitting a new flywheel is applied. Await in anticipation...
Thanks... Lostan...

[dobbslc]

Probably just age but check the end of the crank isn't bent causing the rotor to hit the windings etc.
Some people do just hit the thing with a large hammer trying to get the flywheel off!

[LostanFounds]

Thanks,
Yeh, end of the crank looks Ok.
It was just the mild steel inner lining that crumpled at the weld.
At a glance none of the windings were affected but have sourced a spare anyway.
Am I right in saying every flywheel is balanced at Honda.?
Is this done in conjunction with the crank.? Are they a pair.?
Or is drilling a flywheel to balance the flywheel.?
Guess it's a minor concern.
Gasket set has arrived so will be up and running soon.
TBC... Lostan.

[VFRkieran]

Bit off topic but what HRC bits have you got fitted mate?

[Ben_OB1]

Thanks,
Am I right in saying every flywheel is balanced at Honda.?
Is this done in conjunction with the crank.? Are they a pair.?
Or is drilling a flywheel to balance the flywheel.?
TBC... Lostan.

Yes flywheel is a balanced item. It is not a matched item so can be interchanged with another. If material has been lost from crankshaft this may affect the dynamic balance, otherwise you should be ok to simply bolt a new flywheel on.

Ben.

[Cammo]

If you're thinking of changing it for another one just be aware that there are 2 different types of flywheel and stator fitted to nc30's, neither is compatible with the other stator (if that makes sense).

Early models had Hitachi brand stators, later had Nippon Denso, the flywheel is marked to identify which one it will fit.

Info here: http://www.akhara.com/nc30/nc30parts/files/8.htm

[Neosophist]

If you're thinking of changing it for another one just be aware that there are 2 different types of flywheel and stator fitted to nc30's, neither is compatible with the other stator (if that makes sense).

Early models had Hitachi brand stators, later had Nippon Denso, the flywheel is marked to identify which one it will fit.

Info here: http://www.akhara.com/nc30/nc30parts/files/8.htm

Hey Cammo,

Have you tried swapping them over?

I could be wrong here (I know the NC24 has two different sizes of stator so they are not interchangeable) but from my memory of the VFR the only difference was the supplier.. the actual size was the same so you could chop and change..

could be wrong thoug!!

did notie that you can still buy the flywheell.. 800gbp though.

eek.

[LostanFounds]

Thanks for the replies/advice guys...

I'll check it's the same make both engines 'K' models so believed to be Hitachi stators.
Hi Cammo, when you say, not compatable why is this.?
Do they look different or are the fittings not the same.? (Not the case for me.)
Is there a preference for NC30 riders/racers.?

Hi VFRkieran, I've got a HRC programmable ignition system and HRC jetting and Carb modifications.(No Airbox)
Well it's nearly together, once squeezed in the frame should have a result eitherway.
Cheers...

[Cammo]

If you're thinking of changing it for another one just be aware that there are 2 different types of flywheel and stator fitted to nc30's, neither is compatible with the other stator (if that makes sense).

Early models had Hitachi brand stators, later had Nippon Denso, the flywheel is marked to identify which one it will fit.

Info here: http://www.akhara.com/nc30/nc30parts/files/8.htm

Hey Cammo,

Have you tried swapping them over?

I could be wrong here (I know the NC24 has two different sizes of stator so they are not interchangeable) but from my memory of the VFR the only difference was the supplier.. the actual size was the same so you could chop and change..

Yeah I've run into compatibility issues before between the generator and flywheel, though I'm assuming that all standard parts were fitted at the time!