johnson140,suzuki,2005, overheat

[Lesg]

Hi, am new to this forum and would really appreciate some help;;;;;
This engine is made by Suzuki and has 218 hours on it and has always been run in a spring fed, clean lake. I can run all day at about 1/3 throttle, however, if I go full throttle it overheats in about a minute and drops to the under 3000 rpm mode. I have a strong stream out of the pisser.
I can shut the engine off and immediately restart and it is fine with no over heat indicator.
I have replaced the water pump impeller, no change.
I replaced the water pump housing since the impeller had been upgraded, no change.
I tested the thermostat and it opens at 140 degrees in a bowl
I checked the waterpressure regulator and it looks like new.
all water cavities I can see while removing these items are clean and look like new.
I replaced both temperature sensors, no change.
I also changed oil and spark plugs since this started.
The engine does not have a water temperature gage so is there a way I can check to tell how hot it is getting? Also, what is the proper water temperature for this engine?
Any suggestions?
Does this engine have water deflectors? If so, is this a posibility and how do I get to them to check?
I really need help.
Thanks in advance,
Lesg

 

[reeldutch]

Re: johnson140,suzuki,2005, overheat

im 99% sure its the exhaust temp sensor.
happens all the time on these motors.
just REPLACE the sensor and your alarm wil be gone.

 

[Lesg]

Re: johnson140,suzuki,2005, overheat

Thanks and a good suggestion, reeldutch. I thought so as well, so the 2 temp sensors that I replaced were the Cylinder Temp Sensor and the Ex Manifold Temp Sensor.
This is why I am so perplexed as to the cause of this problem.
Are there any deflectors that I am not aware of?

Thanks in advance,
Lesg