Heres Pic.

[Neal Van]

What Do You All Think

[Neal Van]

What Do You All Think

PICS.

[xlint89]

Ouch. The question is, do you need a new crank now because of the damage? Nice pics.

[ph2ocraft]

Man that red loctite is important...

[Modtodd82]

Hey guys, just to let you know the key is not needed to retain the flywheel, its only purpose is to position the flywheel corectly for the proper timing. I have run several engines with no key due to custom/modified stator/flywheel combinations. There is little load on the flywheel and the tight fit of the tapered shaft (and tight loctited nut ) is all that is needed for keeping the flywheel properly positioned. Get a new key, clean up the crank and flywheel as best you can and then put it together an make sure to properly tighten the loctited(271 red) nut. And, for peace of mind, grab a timing light and verify the timing.

[Hydrotoys]

As bad as that snout looks, I'd consider "lapping" the snout and flywheel with some valve grinding compound, then cleaning it.

[xlint89]

Hey guys, just to let you know the key is not needed to retain the flywheel, its only purpose is to position the flywheel corectly for the proper timing. I have run several engines with no key due to custom/modified stator/flywheel combinations. There is little load on the flywheel and the tight fit of the tapered shaft (and tight loctited nut ) is all that is needed for keeping the flywheel properly positioned. Get a new key, clean up the crank and flywheel as best you can and then put it together an make sure to properly tighten the loctited(271 red) nut. And, for peace of mind, grab a timing light and verify the timing.

Not doubting what you've done as far as mods. But why did the key shear if there is no force applied to it?

[Modtodd82]

Not doubting what you've done as far as mods. But why did the key shear if there is no force applied to it?

Loose flywheel nut. If the nut is tight and the crank and flywheel are tapered and everything is as it should be it would not have sheared the key. The drive Clutch on a snowmobile is a tapered opening and fits on a tapered stub on the crankshaft, there is nothing holding it from slipping but the tension of the retaining bolt and the tapered fit of the crank & clutch. The sleds are putting out a lot more horsepower then any of the pwc's per cc of displacement. I've seen dyno runs of the SkiDoo MachZ putting out over 180hp 1000cc two stroke twin, and I've read of Arctic Cats big engine putting out close to 190hp. And, the only thing keeping the clutch from slipping on the crankshaft is retaining bolt tension.