Looks like I might have broken another crank. If anyone knows someone who has a stock crank they will part with, let me know.

 

Sorry to hear that, do you think you've reached the Hp limit for the stock parts or is it some other problem such as detonation?

 

Magneto break off?

Do you have the lightened flywheel?

How high do you rev it?

 

What happens is the magneto twists off the crank. the magneto is very heavy, that combined with the resistance of the stator from the magnet. Maybe also the 11,000 RPM limit is stressing the crank until it breaks.

I have the PAMI lightened flywheel

 

hey scoob, u said the magneto twists off?! [img]i/expressions/face-icon-small-shocked.gif[/img] is there some kind of imbalance in the magneto that is causing the crank steel to fatigue and fail?
i'm not quite clear on how its failing, is it twisting the stub off where the magneto/flywheel mounts to the crank, or is it coming loose and spinning on the stub of the crank, sounds like it broke though, (twisted off), my guess is the drag of the magnets at 11k rpm might be unbalancing it causing a harmonic that fatigues it to failure. or it might be unbalanced a hair, as rpms go up i think an unbalanced mass increases exponentially in weight.
and my far out thought for the day is adapt a smaller stator and magneto/flywheel off a sportbike engine, they redline at 14,000 stock. and a smaller lighter flywheel might be better for the revs yer running....laterzzzzzzzzzzzzz, josh..... sorry don't have a crank for ya though...[img]i/expressions/face-icon-small-smile.gif[/img]