I'd take the cylinder off and see if the crankshaft will turn (hold on to the timing chain) . If it won't make it all 360 degrees around it sounds like the piston might be hitting the crankshaft? Anyway if it turns OK, start putting it back together piece by piece checking that the crankshaft will keep turning as you go. Leave the spark plug out and keep the cylinder oiled to help things along. Are you using the starter or turning it by hand?
|