2005 350 mag mpi mie overheating

[Garybly]

Hi , installed new sea pump, circulating pump and thermostat, still overheats at any rpm, had manifolds off did not look clogged. Standard cooling system. Do both 7 inch riser gaskets suppossed to have the pinhole gasket on both sides? Any help appreciated. boat also has v drives

 

[Bondo]

Hi , installed new sea pump, circulating pump and thermostat, still overheats at any rpm, had manifolds off did not look clogged. Standard cooling system. Do both 7 inch riser gaskets suppossed to have the pinhole gasket on both sides? Any help appreciated. boat also has v drives

Ayuh,..... Welcome Aboard,........ If you mean you have riser blocks 'tween the manifold, 'n elbow riser,..??
I'm pretty sure, that if so, you need the 4-hole open gasket on the manifold, then the riser block, a small hole gasket, then the elbow riser,.....

Are you using just the dash heat gauge,..??
How hot is hot,..??

 

[QBhoy]

Fair chance that you might have fried the exhaust flappers and they are blocking the cooling flow on its way out…that’s if she overheated previously.

 

[Garybly]

Yes I am using the dash gauges, has new sending unit, 192 degrees, then alarm goes off. Where are the flappers, in the muffler?

 

[Garybly]

Yes the gaskets between the riser and elbow, some sites say full flow gasket others say partially restricted on the cooling hose input side