Larson 77 Shark
Recruit
- Joined
- Jun 15, 2014
- Messages
- 2
Hello Everyone,
I've just inherited a 1977 Larson Shark w/ a 120/140 mercruiser i/o SN 3514130.This boat has never hit salt water. The boat had been sitting for about two years. The engine starts fine even when hot so that makes me think that it has to do with exhaust if the rings and pistons arent swelling. Water still comes out of the prop, however once it heats up, nothing comes out of the exhaust ports by the bellows. No hard starts, no vapor lock. I've replaced the lower water pump, old pump looked great, no scoring, no broken fins. Reinstalled, still overheating. Removed water pump on engine, same thing still looked great, still overheating. Removed thermostat entirely, still overheating although it takes about 10 min to get to that point. Changed out Water temp gauge and sensor on the chance that the gauge went. Still overheating. What is next? I attached the hose to the manifold where it comes out of the thermostat and water pored out of the exhaust ports and propeller. Wouldn't it come out of the water pump first since it has to travel up the riser before coming up the exhaust? Is there any way to check the riser without removing it? Lastly is there a way to flush the system? If so how? Any help would be greatly appreciated.
I've just inherited a 1977 Larson Shark w/ a 120/140 mercruiser i/o SN 3514130.This boat has never hit salt water. The boat had been sitting for about two years. The engine starts fine even when hot so that makes me think that it has to do with exhaust if the rings and pistons arent swelling. Water still comes out of the prop, however once it heats up, nothing comes out of the exhaust ports by the bellows. No hard starts, no vapor lock. I've replaced the lower water pump, old pump looked great, no scoring, no broken fins. Reinstalled, still overheating. Removed water pump on engine, same thing still looked great, still overheating. Removed thermostat entirely, still overheating although it takes about 10 min to get to that point. Changed out Water temp gauge and sensor on the chance that the gauge went. Still overheating. What is next? I attached the hose to the manifold where it comes out of the thermostat and water pored out of the exhaust ports and propeller. Wouldn't it come out of the water pump first since it has to travel up the riser before coming up the exhaust? Is there any way to check the riser without removing it? Lastly is there a way to flush the system? If so how? Any help would be greatly appreciated.