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Ask Dominick Your Own Question
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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07 150 efi. runs hot ONLY when at minimum on-plane speed.

Customer Question

07 150 efi. runs hot ONLY when at minimum on-plane speed. baught a sending unit and gauge to verfy it is actually hot. have replaced popet, both thermostats, and water pump.
where is best place to put sending unit?
Submitted: 1 year ago.
Category: Boat
Expert:  Charles replied 1 year ago.

Hello, my name is***** will assist you today.

It the motor a 2 or 4 stroke?

Would you please post the serial number of your engine so that I may look it up?

Customer: replied 1 year ago.
2 stroke. sn not available
Expert:  Charles replied 1 year ago.


What type or brand of sending unit did you pruschase?

Does your boat have a water pressure gauge? If so, what is the pressure when running at WOT?

When was the impeller last replaced?

Has anyone looked at the tuner on the engine?

Customer: replied 1 year ago.
not sure, it was purchased by dealer.
boat does have pressure gauge. cant remember exact reading but it was OK.
by impeller I assume you mean water pump. it has less than 8 hours on it.
I have never heard the term 'tuner' in relation to this motor.?
Expert:  Charles replied 1 year ago.

The tuner is actually the exhaust tube, it channels the hot exhaust away from the block. It is located inside the mid housing. These are sort of known that on an engine that is getting hot, the nylon in the lock nuts melts out and they fall off. There by blocking part of the exhaust of the engine. If it is either really loose or off, you can shake the engine hard when it is trimmed down and you will hear it rattle inside the bucket. Part 26

Expert:  Charles replied 1 year ago.

Do you still have the package that the sender came with?

Customer: replied 1 year ago.
I do but don't have access tonight. what all can trigger the overheat beeper?
Expert:  Charles replied 1 year ago.

Is this a solid tone or a beeping signal?

Customer: replied 1 year ago.
Solid As soon as I turn it off and back on it will crank again
Expert:  Charles replied 1 year ago.

With no alarm? For how long without the alarm?

Customer: replied 1 year ago.
As soon as I turn the engine off and immediately crank it the alarm goes away
Expert:  Charles replied 1 year ago.

Is your boat equipt with a working volt meter? If so, what is the running voltage of the engine? Overcharge on a battery will also cause a solid alarm.

Customer: replied 1 year ago.
it runs at around 13v
Customer: replied 1 year ago.
Attached sn picture.
Customer: replied 1 year ago.
Didn't work.
Expert:  Charles replied 1 year ago.

Has any of the techs used an IR thermometer to see if the engine is actually getting hot?