Mercruiser 350 engine temperature

[Capt.T]

I recently had my 350 cu.in. Mercrusier outdrive resealed due to milky gearlub. At the same time I had a new water pump impeller installed. Now, while running on plane at 3200 rpm the water temperature rises from 140 degrees (normal) to 175 degrees. A mechanic stated that the water pump tube, which connects to the water pump housing may be broken or separated and not sending water to the engine. I suspect it may be the engine thermostat. Any advice?????

 

[sculbert]

Re: Mercruiser 350 engine temperature

Does it get any higher than 175? The thermostate isn't suppose to open till 160. 15 degrees above would seem to be a concern to me. Maybe everything is just working right for once.

 

[kcole683]

Re: Mercruiser 350 engine temperature

If its a raw water cooled motor shouldn't it run closer to 145 degrees ??<br />I thought the normal raw water cooled t-stat was 143 degree opening. So normal would be from 143 to 160 or so.