Outboards cooling off!

[capeannmakos]

A question. I have a pair of 1994 175 HP carbed 'rudes. When I start up the engines, both warm up to 160 F as per the temp gauge. As soon as I open them up, engine temps drop to bottom of temp gauge. Put new tstats in one engine, no change. I am guessing that under open throttle, the tstats are being pushed off their seats and water is blowing by? Anyone run into this? Or is this even a problem? Thanx for any insight.

 

[clanton]

Re: Outboards cooling off!

Normal. The 160 a little high, probley the guage.

 

[j_k_bisson]

Re: Outboards cooling off!

Yes this is a normal condition with these motors. My 225 when idling is around 160'F range. When I hit 1200RPMS the temp drops to 120'F. How this works is at a certain predetermined RPM, the water pressure caused by the water pump lifts/opens the t-stats off the seats. This allows water to continuiosly trickle down the water jackets in the heads. Thus lowering the temp at the senders in the heads. There is limited water in the heads at idle due to the water only passing by the t-stat orfice when getting hot.

Hope this helps....

 

[capeannmakos]

Re: Outboards cooling off!

Yes, this helps. So no concern. Thanx for the replies!