Ignition timing woodruff key

[bjobotts2]

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Is the bike fixed yet?? Trying to figure out why flywheel is shearing off woodruff key in shaft. Ist time the nut was loose. Second time though nut was tight...but had formed my own key which fit perfect in depth/width, but was a little short. Rocket key off ebay??? What size..3mm? Does it matter if key too short?? My cat says hurry up...please.

[enu06]

Are both the slots clean, and the sides not beveled or distorted?
The only other thing I can think of if as you say the key is a perfect fit is it may have been too tall, not allowing the faces of the shaft and magneto to come in full contact, and stopping it from bolting up really tight. Don't be tempted to make another from harder material, it may not shear, but bugger up the sides of the slots, instead of/or before shearing, they are crucial!.

[bjobotts2]

How far does the shaft extend through the nust when the flywheel is all tightened down 'cause the nut on mine doesn't even tighten down even with the end of shaft. There's still about 3 threads left in the nut to make it even with shaft yet everything is so tight that feels if I turn nut one more time shaft will break. Looking for pics on this site where I can see the flywheel nut.

[Badobsession (the real one)]

Should be on more than that is it the original nut or have you changed it?

[enu06]

Try fitting without the key and tighten up as you would to finish the job, this will show up any bad fit with the key. Don't run the bike though, (obviously) then take it apart and refit the key, it still sounds to me that the key is too tall, this would stop the mag from going on enough, and make it appear the the shaft is too short. File down to fit, perseverance required.

[bjobotts2]

Refiled the key making it shorter (as in not tall) and nut did tighten down all but one thread(looks normal). Started right up and has power but now making a rattling noise wasn't there before. I re-gapped the valves (They were normal)...drove it around the block and runs great except for noise. For some reason I'm too paranoid to drive it very far yet.as afraid it will shear off key again...gotta get over that. Going for a longer drive and hope don't have to push it back, ha. Thanks for the advice, it really worked for me. Still thinking about buying a rocket key just to have in case this comes up again.

[jialing]

I dont know why people are finding it hard to get woodruff keys.
They are used in almost every outboard marine motor, one for the flywheel, and another as a shear pin on the prop shaft.
Because different manufacturers make different size engines most marine outlets would carry a wide variety of shapes and sizes to fit the various engines.
If your really pushed for a key look up boat dealers, repairers or even boat chandlers they may be able to help. Who knows you might even get the exact fitting one for your bike. It might pay to also get a spare that might come in handy in emergencies.
Hope this helps someone in the future. regards alan

[enu06]

Is the rattling noise there all the time? It could be the variator rollers, as they wear mine have done the same, not really a problem, but they may have gone oval too. They will keep on going for ages if it is them, but bear in mind they will need changing reasonably soon.
You could try starting the engine and getting a long srewdriver or simular and putting it against different parts of the engine, and putting the other end to your ear like a stethoscope, this could also point you to where the noise is coming from.