Overheating 85 Merc 150hp XR2

Joined
Jul 9, 2008
Messages
13
Hi there,

My engine overheats soon as its passes 5200rpms underload.
I can come off the gas when it does this and idle it in neutral to 3500rpms
and have it cool off real fast.

I've replaced my impeller,bolth thermostats(120 degrees C) and poppet vale.
My tell tale pisser is pissing good.

I notice that it will go over 6500rpms at full trottle with no trim.
This is a 17 foot edson ski boat.

I've got a quicksilver ss prop.It says 25p which im guessing is a 25 inch prop.
I think I'm over proped which is causing an overheating issue????
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Overheating 85 Merc 150hp XR2

6500 on an XR2 is not over propped for sure. The piece of info needed is water pressure at various speeds.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Overheating 85 Merc 150hp XR2

Stock mercury dash gauge. Look in the accessories page of the parts for your engine. Hooks in to a pipe port just aft the flywheel in the top of the engine. There could be a hose there, or a plug now.

hope it helps
John
 
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