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2002 F115 4-stroke flywheel loose

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bobev

New member
I have a identical problem as another member, flywheel came loose, broken woodruff key, shaft nut came off. I owed engine since new without prior work. I had a certified tech replace trashed stator, new key without new flywheel. He torqed nut down. Within ten minutes in water the nut was loose and key broken again. He says its not the flywheel but some mistory harmonic vibration. Does anyone have any idears?? Thanks:confused:
 
Have them use a small amount of valve grinding compound to " lap " the tapers together.----------Generally the key locates the flywheel.----The flywheel is driven by the locking tapers.-------------Flywheel key to be used must be a factory replacement.
 
racerone said:
Have them use a small amount of valve grinding compound to " lap " the tapers together.----------Generally the key locates the flywheel.----The flywheel is driven by the locking tapers.-------------Flywheel key to be used must be a factory replacement.
Click to expand...

The flywheel colar were the key slot is has soon scareing and abrasions from first key breakage, tech says its ok. All this does not explain what caused first failure after 10yr and 566hr on engine???? I'm afraid problem not found.
 
Lap the tapers together.--------If they are not perfect they do not fit properly and the key ends up driving the flywheel.-----------The key was not designed to do that !!!!
 
racerone said:
Lap the tapers together.--------If they are not perfect they do not fit properly and the key ends up driving the flywheel.-----------The key was not designed to do that !!!!
Click to expand...

Sorry, I do not understand, lap tapers together???? There are not any tapers other than the whole shaft has a taper, it is a smooth taper from top where the threads are to the bottom and the key is about half way down. The flywheel is lined up on the key and the 250lb torqe on the nut is supposed to press the wheel down on the tapered shaft. This is what the mystory is what is causeing this to losen. If anyone has any ideas please help.
 
USE VALVE GRINDING COMPOUND ON THE TAPER OF THE FLYWHEEL AND THE TAPER OF THE CRANKSHAFT !!-------A thin smear will do it and rotate the flywheel on the crankshaft so the 2 tapers will clean up and match properly.-----This is standard machine shop practice.-------If your mechanic does not understand this than hurry find one who does.
 
I thank you for your response, but this does not address the initial problem. After ten years, what caused flywheel nut to come loose, there had been no prior work done and the original tapers were smooth and tight from beginning. I don't see this correcting the problem. If anyone has had this occur please let me know what finally had to be done to fix problem . Thanks again
 
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