Mercruiser 4.3 starboard manifold too hot.

Rov7773

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Joined
Aug 8, 2019
Messages
4
Hey guys first post here. I have a 2001 searay 185 with the mercruiser 4.3. Only owned it for a year. Last season the boat dint seem to have much power, after turning it off and swinging for an hour or two it would take up to 2 hours for the boat to start again. When it wouldn’t start it always got fuel spraying out of the injectors, so I guess that ruled out vapor lock. Anyways I realized the starboard Manifold would get very hot (180, port about 95 to 110). I just figured bad manifold since it had the one piece design. I let the boat sit winterized and just installed new 2 piece manifolds, raw water impeller, thermostat and complete tune up. It still runs very hot on the starboard side on the muffs, I even used a very large bucket and ran the hose into it, to rule out low water pressure from my house.
Starboard Manifold gets to about 180 before I shut it down and port hovers about 110 to 115 tops. The thermostat housing does not have the check valve in it. While running if I undo each hose to the manifold from the tstat they seem to be getting the same amount of water. The exhaust shutters are in place. The old impeller was in good shape and compression is good. Not really sure where to look from here. Maybe pull the whole alpha drive to see if anything is plugging the exhaust? Thanks for any help.
 

Rov7773

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Joined
Aug 8, 2019
Messages
4
Also, the engine itself ,according to the gauge never gets over 170. It almost seems like the starboard side of the engine itself is running to hot, maybe blockage in the cooling ports of the engine block
 

Rov7773

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Joined
Aug 8, 2019
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Okay will do, used bucket l just as a test, does the same on muffs. Going to try and get some clear hose to see if I have any air in the water coming into the engine.
 

xltier

Chief Petty Officer
Joined
May 20, 2004
Messages
636
try pulling the hose off the thermo-stat housing and start the motor. should have a strong stream coming out and not alot of air bubbles. i once found a garden hose i was using had a very small hole in the fitting at the end to.worth checking
 

Rov7773

Recruit
Joined
Aug 8, 2019
Messages
4
Hard to tell if it has any air bubbles but from what I can see it looks okay. Has good flow, it’s not like gushing out but it seems good. Maybe I don’t even enough water pressure at my house, I have well water.
 
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