Overheat at high rpm's

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,110
2001 125 Mercury
New impeller, housing good, wear plate good, new poppet and parts, new thermostat etc.


It can run all day at 3/4 throttle.
Hit wide open, it overheats.
The cooling passages clear.

Thanks, Jerry
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,265
Check the head bolts for proper torque. Leaking combustion gases can cause overheat.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,931
Head bolts??????:lol::lol:
Check for bottom damage or obstructions in front of water intakes as these motors cannot stand a lot of engine height due to intake location.
 
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