are you using a tusk flywheel/clutch holding tool and a breaker bar to remove the flywheel nut ?
if not, do so and it will/should come right off.
you can test the stator coils with an ohmmeter, while still installed, through the wire connections right above the kicker, although not foolproof and absolute, may lead to some clues if the coils are good or not
that electrical troubleshooting can be found near the end chapters of the manual, found here.......
http://www.blasterforum.com/general-support-17/downloadable-yamaha-blaster-manual-17325/
cheap yet effective multi/ohm meters can be had at harbor freight or radioshack for under $10