1990 200 hp gt overheating

[Aquanut1]

I pick this motor 6 months ago. I was sitting a while so I changed the stats, impeller, plugs, wires, had the carbs done, and the crank gasget replaced. $1500 later I have a cooling problem that wont go away. I have 25 lbs of water pressure, and it still overheats at full throttle after a few minutes. The dealer that took the motor apart said it was in very good shape for a 1990 and clean inside. The plugs are the correct heat range. The fuel mix is correct at 50:1.Plugs look ok after runing awhile. Reading back in the forum history someone mentioned water deflectors. Could that be causing my problems? Could it be a bad prop?

 

[Dhadley]

Re: 1990 200 hp gt overheating

Your motor doesnt have deflectors. <br /><br />Describe the warning condition. How do you know its overheating? does it go into SLOW (about 2500 rpm max)?<br /><br />If the rpm isnt limited to 2500 and you have a continous horn it could be a fuel restriction warning.<br /><br />Tell us more about what actually happens.

 

[Aquanut1]

Re: 1990 200 hp gt overheating

Along with the heating problem i seem to have a prop problem. When it overheats an alarm sounds and it goes into slow mode. It doesn't overheat at 5000 rpm only when it gets to 6000 rpm for a few minutes. I was told that it should max at 5500 rpm's. I was going to get a prop when I got the heating problem fixed. Thought I call the prop guy and got a loner prop to check to see if the pitch was right. I went from a 14 1/2x 19 to a 14 1/4 x 21. I think i understand why its overheating. The motor is to high. I had been blowing out around corners with the 19 pitch but the 21 pitch is making a giant rooster tail with less speed. I think the motor is sucking air. So I droped it a hole.I'll need to take it out again tomorrow and see. Is my thinking right or should I be looking for something else?