Overheating at an idle. Mecruiser 260

[CAPTKEV85]

I have a 1985 sea ray with 260 mercruiser. At idle it overheats in 3 mins once you go over 1000 rpm's it cools down. Last year I put new thermostat 140 and it still had problem. Then I put sea water pump in drive. Still same problem. Boat has new risers and manifolds too. Any ideas? Thanks

 

[Bondo]

Re: Overheating at an idle. Mecruiser 260

Ayuh,... Water's gotta get in, 'n back out...
Have you tested any of the Flows, anywhere,..??
Pull the in-coming line off the T-stat housing, Any flow there,..??

 

[CAPTKEV85]

Re: Overheating at an idle. Mecruiser 260

I'll give that a try tomorrow.