Hi, I'm a small one man band running on the smell of an oily rag and a small number of properties on the weekend. I recently bought a very cheap, used and 'probably dead' fs90r in the hope that I could reduce use on my fs94r- I'm wondering if it is repairable. I make do with my own maintenance with no training (another reason I love this website!) but have never had to take a 4mix apart or do valve work. Pulling on the cord I end up with a hard stop. On partial disassembly, I can spin the flywheel and the exhaust valve will move - when the piston gets to the top, it stops. When I reverse the flywheel, the piston doesn't drop, but with a scrench in the spark plug port I can push it down and repeat the process. I can't see much through the exhaust or spark plug ports on a 4mix! Can you give me any guidance? Would this be a bent or dropped valve? A crankcase problem? Would it be worth pulling off the valve covers or is it complete disassembly or just not worth doing? I'd hate to have to take the hit on the cost of this with nothing to show for it.