1990 Mariner V150 Overheating Question

[Astro18]

My 1990 Mariner V150 seems to run hot at speed of 20+, but seems to be fine at speeds under 20 all the way down to idle. I flushed it (as good as I could) but it still does it. Where should I go from here??<br />To clarify...the temp gauge reads just under 3/4 when idle or under 20...but shoots up almost to hot when over 20mph.

 

[jim dozier]

Re: 1990 Mariner V150 Overheating Question

Outside of the temp gauge are you getting any warning buzzer or lights or evidence of engine overheating? Can you put your hand on the block between the flywheel and the cylinder head for 5 seconds without burning yourself? Is this a new situation for the engine or just new to you?

 

[Astro18]

Re: 1990 Mariner V150 Overheating Question

I didnt pull the cowl when it was doing it....but I do remember that the cowl seem hot, so it's safe to say that the engine was even hotter. I'm sure it would have been too hot to touch.<br />It's always ran at about 3/4 on the gauge, but it just started doing this running hot thing.<br />No buzzer or other warnings, other than the gauge.

 

[jim dozier]

Re: 1990 Mariner V150 Overheating Question

How's your pee stream? Simplest thing to check is to see if your thermostat is opening all the way and at the right temp. Remove and check in pot o boiling water with cooking thermometer. Next in line would be to replace the water pump.