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exrider23
10-29-2006, 08:03 AM
Ive seen where people put flywheel keys in. What is it and what does it do?
GPracer2500
10-29-2006, 02:20 PM
The flywheel key (also called a woodruff key) aligns the flywheel on the end of the crank. There's a slot on the flywheel and a slot on the crank--the key fits in these slots. This is what a typical woodruff key looks like:

http://www.mfgsupply.com/img/rotary/02-33.jpg

Some flywheel keys allow the flywheel to sit on the end of the crank twisted a little bit from the stock orientation. Since the pulse generator that triggers ignition is timed off of the flywheel, moving the flywheel will change the ignition timing. That's the point of doing it--advancing the ignition timing.
krt400ex
10-29-2006, 06:04 PM
Originally posted by GPracer2500
The flywheel key (also called a woodruff key) aligns the flywheel on the end of the crank. There's a slot on the flywheel and a slot on the crank--the key fits in these slots. This is what a typical woodruff key looks like:

http://www.mfgsupply.com/img/rotary/02-33.jpg

Some flywheel keys allow the flywheel to sit on the end of the crank twisted a little bit from the stock orientation. Since the pulse generator that triggers ignition is timed off of the flywheel, moving the flywheel will change the ignition timing. That's the point of doing it--advancing the ignition timing.



yupp^^^^ and advancing the timing will give u better bottom to mid, and better throttle response...i did it to mine...they r well worth the $20
pdracer440
10-31-2006, 06:20 PM
OK, was reading some more info on the flywheel key and according to the Sparks web page, they only recommend this mod for stock motors due to the extra heat the advanced ignition will cause. Any one have one on a 440 or would it be a waste of time?
krt400ex
11-01-2006, 07:35 AM
it would be fine as long as u can keep ur motor cool...if u have to add an oil cooler than do it. my friend owns a shop, and he pouts the key in evry ex motor he builds, and he has never had any probs with it. he build 440s, 426s, 416s, 440 strokers...the whole thing. just go for it, u will be fine