Promax 300 - running too cold!

[Toffen]

Hi!

I trust you are well.

I am running too cold in the spring and early summer. The engine temp is below 115F at cruise (3.500-4.000 rpms) and the engine is fauling and using lots of gas too.

Last year I had the same situation for two weeks, but this year the sea temp is very low in June. Apprx. 10 degree Celcius.

My tech made a adjustable poppetvalve two years ago, and this restrict the waterflow into the engine. However, the waterpressure increases as well. Max psi is according to Merc Hi Performance not to be higher than 25 psi. So, the temp is still too cold when I hit 25 psi at wot.

I have plugged 3 holes on each side of the lowerunit. This dropped the waterpressure, but I am still running too cold....! Temp is just fine at wot - approx. 130-135F. Thermostats is set to open at 142F. They are new and in order. At idle temp is approx. 145F.

I look forward to hearing back from you.

Cheeers, Toffen - Norway

[at100plus]

I just changed the water pump on mine, and I couldn't believe the difference in temp. I thought my guage broke at first. At idle and slow speeds I barely got a reading, at top speed it came up to the first mark. Don't have an answer for your problem though.

[WATERWINGS]

I am having the same trouble......water temp @75 degrees.......

Read the post, "ITS ALIVE"

[nic]

we are having the same problem here with 330x's mercury re wrote some new brains for us as we kept going thru plugs at slow speed mint if motorwas run only hard out