I dont know a whole lot. But i would check the risers. They could be rusted out causing water to leak down into the cylinders, could be hydro lock. Pull the spark plugs out and bump the motor, water should come out if thats the problem. if the plugs are black change them, mark the wires so you dont mess them up like i did
.... a side tip check anti freeze level and if there is any antifreeze down in the cylinders change the motor oil quickly.
