I have a 89 merc 135 black max and the heat gauge is divided into 4 quarters. Where should the heat level stay while cruising across the lake? Thx for the help.
That is a very broad question. Depends? Idleing and low rpm I would think it would run in the areas between 1/2 - 3/4 and running across the lake as you put it, about 1/4 mark.
Well heres the deal, running across the lake @ 4 to 4500 rpm the heat hand was at 3/4. This is my first boat so im not sure if thats normal or not. I just dont want to harm the engine.
As long as the overheat alarm doesn't sound, you are ok. Now, here is a question for you. Can you see the temp go up when running slow and then as you pick up speed and RPMs, does the temp drop any? Do you have a water pressure guage? That way you can see the pressure drop when the poppet valve opens to release excess water through the exhaust. Could be some small junk is hindering the flow in the small poppet valve area.
No there is no gauge. I didnt notice it at low rpm's just when i was at runnin bout 4500. The heat hand went up a lil over 3/4 but after a while went down and then back up. The motor is spitting water fine so this may just be norm operating temp. That motor has an alarm that sounds when it overheats? What about if it stop oiling?
