hey there i recently bought a 91 550sx and rode it around for a bit just fine and all of a sudden it stopped working. it will only crank just once. i took off the hood and can see that the crank wont go past a certain point but i cant seee anything stuck in my impeller! i can move the crank shaft back a little but keeps stopping at the same spot. im almost positive its not something in the impeller because the lake was clear and i didnt sound like the other time i sucked something up. any ideas on where to start taking it apart?