Running hot on one side

[wellcraftexcelcrap]

Ok, I have a gm 350 crate engine with vovlvo sp drive in a 93' wellcraft excell 23se raw water cooled All of the sudden the temp gauge started reading apx160-170 should be at 142 or at least that is where my thermostats is set to open. When I feel the engine one bank is way hotter than the other. Left side is hot looking aft. Also it looks like I have a sheen of gas or maybe oil in my exhaust. I also had a guy tell me I was running rich on one side after he changed out my spark plugs. I seem to be getting really good flow out of both sides of exhaust and recently changed out my manifolds and risers. Also impeller was recently changed. My game plan is to first change/inspect oil for water. Next do a compression test. I also want to take my carburetor off and have evaluated as it looks like prior owner fed with it and put it back on with gasket stealer. Any other recommendations on where to start would be helpful.

 

[captmello]

Does it cool down if you back off the throttle to idle speed? Sometimes the water intake at the outdrive can leak air into the system when the boat is on plane causing it to overheat on plane but cool back down when the boat is stopped and the intake is all underwater. If the carb is suspect, just have it rebuilt, its not expensive. A compression test is a good measure of the engines overall health, let us know what you find. Btw, the impeller should be replaced every two years.

 

[dypcdiver]

There is a good fault finding instruction in the "Adults only" section at the top of the forum. Might help if the solution is not obvious.

 

[jerryjerry05]

What model?
430A, 430B, 431A, 431B, 432A, 434A, 500B, 501B, 570A, 572A, 740B, DP-A, DP-A1, DP-A2, DP-C, DP-C1, DP-C1 1.95, DP-C1 2.30, DP-D, DP-D1, DP-D1 1.68, DP-D1 1.78, DP-D1 1.95, DP-D1 2.30, SP-A, SP-A1, SP-A2, SP-C, SP-C1 - 7736260
There's a few to choose from??
Some had a flapper in the exhaust down tube.
It might have melted and fallen into the bottom and blocking the exhaust.
If it's running "rich" that'd be a carb problem. One side running rich is more likely it's running cooler than the other.
The flow isn't set up to feed one side or the other.It's divided .
The manifolds how old? Risers, the end clogged?
The pump how old?
The housing (pump) any scoring?

 

[mikeneal]

Sounds like you have a low level overheat that could be caused by lots of things. That side of a SBC is always warmer then the other due to the flow thru the system.