i can fix it, but the shipping cost would probably be more than the repair.
to remove the flywheel, you need to use a puller. a three jaw type is the best. dont hit the flywheel itself with a hammer. you can thread the flywheel nut on the end of the crank flush with the end of the crank, then insert a screwdriver under the flywheel and apply a firm yet not forceful pressure, and then rap the end of the crankshaft with very quick and sharp blow with a hammer. but you want to make sure you hit it squarely otherwise you will damage threads. the nut kinda helps protect the threads, but its not fullproof. it really sounds to me like something fell into the crank case. have you tried turning it upside down and shaking whatever might be in there out?