At the least, you should remove the carb, rear cover, and cylinder head. Use fresh fuel to flush out the engine as much as possible. DON'T turn it over until you've thorougly flushed the engine. Then turn it over very, very slowly, feeling for anything that may want to stop the rotation. If any grit's in the bearing, you'll feel it and not cause damage if you're careful. If you can't flush the grit from the bearing while only the head and rear cover are off, you'll have to do a full teardown.

See Harry Higley's book, "All About Engines" for details on disassembly and reassembly of your engine. There's too much involved for this type of communication. You can order the book through your favorite hobby retailer.