flywheel key

[xcracer416]

do i have to have a different flywheel key when i use i wiesco crankshaft? cause when i put my original key in it and it barley sticks up to catch the flywheel rather than my stock crank was.and what would a sheered flywheel key do?(another 250r)

[wilkin250r]

Originally posted by xcracer416
and what would a sheered flywheel key do?(another 250r)

It would throw your ignition timing off. If the timing gets retarded ( spark occurs later than it is supposed to), you'll be way down on power.

If the timing gets advanced (occures earlier than it should), it will cause detonation or pre-ignition, both which can destroy your motor in real short order.

[xcracer416]

Originally posted by wilkin250r

If the timing gets advanced (occures earlier than it should), it will cause detonation or pre-ignition, both which can destroy your motor in real short order. that would explain alot, it would probally be hard to jet also huh?

[wilkin250r]

Originally posted by xcracer416
that would explain alot, it would probally be hard to jet also huh?

Hard to jet? It would be dang near impossible to start.

If you have a flywheel problem, or an ignition timing problem, jetting is the last thing you should be thinking about.

Would you be checking your lugnuts before you have tires on your rims?

[stever250r]

Please correct me if Im wrong.

I agree that the key is for ignition timing. The keyway on a stock flywheel and crankshaft is to align your ignition timing.

I dont think it has anything to do with holding the flywheel in place. The flywheel should stay in place regardless if the key were to shear. The torque of the bolt basically presses the flywheel onto the tapered crankshaft. Thus requiring the special tool in order to remove the flywheel.

If an aftermarket ignition system is used... such as PVL... there is no keyway on the flywheel. You have to set your ignition timing with a bore caliper and a specific measurement from TDC.

So I would think that as long as you line the keyway slot up in your stock flywheel with the keyway on your crank... it would stay put regardless if the key was actually there or not.


Like I said... Someone please correct me if Im wrong on this.

[wilkin250r]

Originally posted by stever250r
I dont think it has anything to do with holding the flywheel in place. The flywheel should stay in place regardless if the key were to shear.

Yes and no.

You are correct, most likely your flywheel would stay in place. It's on there pretty d*mn tight.

However, if it does stay in place, then the key isn't going to shear, correct? The only way it could possibly shear is if the flywheel moves.

But there HAVE been cases of people having a sheared key. It happens. For the life of me, I can't figure out what would cause it, but there's no doubt that it has happened.

[greenman]

i had a fly wheel that kept shearing keys then i was told bye some snowmobilers that if you take some grinding compound and lap the fly wheel two the crank it would give it a better mating surface and from then on no keys where sheared

[wilkin250r]

Originally posted by greenman
i had a fly wheel that kept shearing keys then i was told bye some snowmobilers that if you take some grinding compound and lap the fly wheel two the crank it would give it a better mating surface and from then on no keys where sheared

Excellent suggestion! I've never thought of that (probably because I've never had a key sheared), but it makes perfect sense. If you lap them together, you eliminate the high spots, so you get more mating surface in contact. More surface equals more friction to keep the flywheel from spinning.