Opersting remperature

[XMP]

SN 2B216247 115hp . What is the correct operating temperature or this engine? Mine never exceeds 125 on vessel view, it makes a little oil, could the two be related? I bought it used and it has 65 hours.

[EuropeanAM]

A lot depends on the running conditions. Are these the temps AT IDLE, or when you're running down the lake at 75% or higher throttle?

A cold-running engine will be RICH, and that can potentially result in what some refer to as "making oil".

Make sure you're using the correct oil/weight, and that oil level is set to 25-33% of the SAFE zone on the stick (NOT TO THE FULL MARK!).

[XMP]

Thanks Don, 125 is at idle. The person I bought it from had it a 23 pitch prop on it and it wold only reach abut 5000 rpm. I put a 19 pitch on it and now it turns 5700 to 6000.

[EuropeanAM]

I would pull and inspect that thermostat just to make sure there is nothing hung in it (or damage). Relatively simple to do on these.

Oil level, type and WEIGHT?

[XMP]

level is maybe 25 or 30% above add mark. Mercury oil, 10w30. Temperature is 120 or 125 running at 5800 rpm. Water pressure is good according to vessel view. I had the oil changed at my dealer.

[EuropeanAM]

We normally use 25w40 in that engine (unless you're regularly operating it in temps below 40 degrees F).

I'd like to see those temps up a little higher on that engine... probably a good idea to pull the thermostat and inspect/test.

[XMP]

Thanks, the oil only has a few hours on it, I will run it a while and then change to 25w40. Should I use synthetic blend or mineral? Is there anything other than the thermostat that could cause the motor to run a little cold, the lake water is 60 degrees. What should the water pressure be at idle and at wot?

[EuropeanAM]

Either is ok to use... the Synthetic Blend is considered the "best" option.

Thermostat is about the only item (other than simply very cold water supply).

Normally 1-5 psi at idle, and at WOT, 11-40 psi range.

[XMP]

I installed a new thermostat and on muffs it warmed up to and stayed at 122. I think this is about 6 or 7 degrees warmer than before I hope this improves things.

[EuropeanAM]

[XMP]

I finally got to run the boat today. At 5800 rpm it was 126 to 130 degrees with 30 psi water pressure. it warmed up to 120 at idle. I think that is more the way it is supposed to run. I thank you Don for being so willing to share all your knowledge with us, all you do is priceless to us.