Removing a Flywheel

[Rey Kirkman]

Hal, Sorry I was non-responsive to your query.  I thought you might be want to actually shave the flywheel yourself.    I have done this job three times now; and it is not easy simply because of the physical force required to remove a flywheel that is well "stuck" onto a tapered shaft. It would help you to have the factory manual.  Cost about $40.  You need this to picture how everything should look.    You need to remove the two left-side covers.  The front cover of the two will seem to be held on unnecessarily - it is the magnetic force of the flywheel - it's magnetized.  With that, the flywheel is exposed. You will lose about a quart of oil. Be careful not to allow the cover to "hang" on its connecting wire - support it or unplug the wires.   You will need a good flywheel puller, an air-driven 1/2" drive impact wrench and two propane torches.  If you don't have the tools, you can't get the flywheel off its shaft.  The flywheel is attached to a tapered shaft by a nut, which is torqued to about 100 ft. lb.  Make sure the bike is in gear.  Once you get the nut off, you'll find that the flywheel is really stuck to that shaft.  Talk to Paul Venus.  He just did it and swore it was one of the hardest jobs to do.  Figure a five hour job.  You will need new gaskets for the side covers.   I think it is important to use a good quality flywheel puller.  I use a Craftsman, which is guaranteed not to break.  It is important that the puller be exactly parallel with the flywheel. If canted ever so little, it will pull the flywheel "sideways" further locking it onto the shaft.  I used a vernier caliper to measure the distance from the puller arms to the face of the flywheel.   I think you can use some heat on the hub of the flywheel.  A gas torch is too much.  A single propane torch is too little.  Use two propane torches and heat the hub until your spit sizzles.  Then get your air compressor psi up to max and use the impact wrench to try to drive it off.  A helper with a rubber hammer can tap/pound on the flywheel when you are applying the impact wrench.  The flywheel will POP off with a bang - so be careful and have a pile of towels below to catch it.    You will have to remove and reinstall the starter clutch assembly, which is mounted to the back of the flywheel.  Note, Yamaha has "crimped" the mounting bolts by means of a drift.  The mounting bolts are allen head bolts.  Use a 3/8" socket for the allen head bolts - your local NAPA store will have the socket.  Be real careful to visualize this clutch assembly and how the little springs go back in place.  Some may have popped out when the flywheel came off - another reason to have some towels to catch parts when the flywheel pops off. If you decide to proceed, I will be available by telephone to walk you through it.  I'm in Oregon - Pacific time. 503.588.3973.   Good luck,   Rey