I would try to turn the engine over by hand first. Us a 1/2" drive ratchet or breaker bar on the crankshaft pulley. If the engine is seized up, you have bigger problems.
Corrosion at connections is probably your next battle. Remove and clean all battery and starter cables. Use a wire brush to clean the posts and ring ends and a battery brush to clean inside the battery terminals.
You may have to remove fuses and clean connections there as well.
REBUILDING HOLLEY MARINE 4160 CARBURETORS - $199 DELIVERED
GENUINE MARINE HOLLEY KIT USED - INCLUDES POWER VALVE UPDATE
LED TRAILER LIGHTS, LUG NUTS SPARE TIRE CARRIERS, SAFETY CABLES....
Originally Posted by Bouyhead
Installed my carb that was rebuilt by thatsmrmastsercraft, Thanks Peter!! Hot or cold this boat starts and runs like it fuel injected.