It's supposed to be a sliding keyed fit on the crankshaft. You need a puller that can pull on the top surface of the blade adapter (the hex shaped thing. The shape is incidental - some of them are round). The central bolt of the puller should bear on the (temporarily re-installed) blade bolt, which should be screwed in about 10 turns.
90% come off with moderate pressure, but there are some which seem to be welded on - if you have one of these get it really HOT and try again. I've had to resort to an air tool on the puller to shift them! (If you try this, take appropriate precautions against flying debris should the puller break). THe heat will cook the oil seal, but you will be replacing it anyway, so it won't matter.
Compare the hassle with the cost of a replacement engine - it may not be as expensiva as you think!
phil_saunders@bigfoot.com
Phil Saunders
July 2008
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