Rotor Assembly Will Not Come Off

[landonshaw]

I am having problems with a 5hp Yamaha. (Photo 1) I have taken off the starter case. (Photo 2) Then removed the pulley starter. (Photo 3) Unscrewed the center nut that secures the rotor assembly to the crank in the cylinder case. (Photo 3) I tried to pulled the bottom portion of the rotor assembly off with a gear puller and actually bent an arm on the puller. It did not move. Is there another nut that needs removed? or is this just so corroded that it won't budge? I have looked at drawing of Yamaha's and it looks like there is no reason other than corrosion that it will not come off. Any suggestions, ideas?

[courageous cat]

put a good puller on it. tighten it up then give the shaft of puller a wack with a hammer it should pop loose

[courageous cat]

You could also try a little heat on the flywheel around were the nut came off the crankshaft

[landonshaw]

Thank you for your comments. As you agreed that the assembly should be able to come off, I made a space a little bigger to get the next size pulley puller attached. With considerable effort, it came off. I did not use the heat because the fuel tank was VERY close, and even with it removed there might have been a problem. Thanks Dave

[thendel]

Yamahas (motorcycles anyway) that use flywheel magnetos such as this often have a female thread inside the depression or recess where the end of the crank protrudes (where the nut was).
The OEM puller that is supplied by the manufacturer has an externally threaded body that screws into the recess and a bolt that bears against the end of the crank, and using that tool is the simplest way - it's worth investing in the puller if you plan on keeping the outboard.
Other than that (as previously posted here) a standard 2 or 3 arm puller and a hefty crack with a hammer should do it.