Starboard riser running hot (just replaced)

[gmcleer]

I just put the boat in the water yesterday after replacing the mainifolds, risers, elbows, impeller, thermostat and circulating pump over the winter. The boat idels at 170 on the guage then runs a little warmer at cruise. I don't know how accurate the guage is. I ran the boat for a few minutes at 3400 rpm and felt the elbows. The port was cold and the starboard was hot to the touch. After a few seconds it was uncomfortable to keep my hand on the elbow. Any thoughts? I am trying to get a hold of the mechanic, but, spring fever is keeping him VERY busy.

Thanks

 

[midway]

Spring loaded check balls in the cooling hoses to the risers, check the hoses at the thermostat housing.

 

[PlayDate]

Were you able to find the problem?

 

[gmcleer]

I haven't had a chance to work on the boat again. Would a blown head gasket show these symptoms?

 

[PlayDate]

I haven't had a chance to work on the boat again. Would a blown head gasket show these symptoms?

I was just starting with what was recently replaced which is why I suggested that the gaskets on the starboard side may have been installed improperly (blocking off cooling). Was there a engine problem before the manifolds and risers were replaced?

-John

 

[gmcleer]

John,

I purchased the boat on 9/06. The mainfolds were original and shot. It seems like the starboard side isn't getting enough water. The entire side is equally warm (mainifold, riser, elbow). The water heater also draws from that side of the thermostat housing. Could the thermostat housing/water heater be part of the problem?


Gordon

 

[PlayDate]

John,

I purchased the boat on 9/06. The mainfolds were original and shot. It seems like the starboard side isn't getting enough water. The entire side is equally warm (mainifold, riser, elbow). The water heater also draws from that side of the thermostat housing. Could the thermostat housing/water heater be part of the problem?


Gordon

Gordon,

Unless there is a blockage in the thermostat housing, I doubt that is the issue. I'll assume that your engine is raw water cooled....meaning that it does not have a heat exchanger that contains anti-freeze.

The simple way to check the raw water flow to the manifold/riser/elbow is to disconnect the feed hose at the thermostat housing for the starboard side. Have a friend start the engine and watch the flow.

For comparision, stop the engine, reconnect the starboard hose and disconnect the port hose, restart the engine and observe.

It is possible that the wrong hose (a water heater hose) got connected to the starboard manifold during the repairs. The exhaust manifold hoses are above the thermostat and are not affected by the thermostat's operation.

-John