*update*1997 DT 225 over heating issue?

[king air pilot]

Hello and thanks,,hope I can get some help. i have a 1997 DT225 (2 stroke). I had the lower unit completely rebuilt with new impeller. I also replaced my thermostats. One was broken in the full open position. this did not fix my issue. What is happening is I can run the boat for an hour or so, sit for an hour. When I go to start it up and get on plane, after about 5 minutes it will give me the over heat warning. I goto idle, turn off the motor, restart and 90% of the time it is ok until I sit for some time again and then same issue. I do have a good stream of water peeing the whole time. i bought an info red (sp) thermometer, I noticed the port side running at about 200, the starboard side running 160-170. I had the muffs on today, and pulled the water house off each side one at a time. I noticed the water flow seemed to be ok and equal on both sides. And today I THINK that the starboard side was the hotter side,,,I did not let them get hot to where the alarm went off. i did use salt x 3 times today to run through the engine....any ideas what is going on? btw this year does not have the water pressure switch...

 

[king air pilot]

Re: 1997 DT 225 over heating issue?

Re: 1997 DT 225 over heating issue?

anyone?

 

[king air pilot]

Re: 1997 DT 225 over heating issue?

Re: 1997 DT 225 over heating issue?

I think I have it figured out! Took off thermostat covers,,ran Rid Salt stuff through the engine through both thermostat openings. Did it for about 45 minutes! Engine, on the inside looks sooooo much better! Ran both with cover off, friend driving. Shot my infrared thermometer on all cylinders top were the hottest, around 145 degrees. Around the sensors it was 220ish. Temps never got hotter. Anchored boat for about 20 minutes. Restarted the engine, it was near 160 for a minute or two,,then back to 145ish... Got the alarm while I was checking temps, nothing ever got hotter than the normal numbers! Turned boat off for about 30 seconds, started back up no alarm. Engine is at its hottest when you turn it off and let it sit for a second and restart. I would think that if it was truly running hot that once I shut it down and turn the key on, that I would get the alarm if it was really over heating??? So I think I just get an intermit over heat from a fault sensor? So I consider the problem not a problem at all! BTW, after running the rid salt stuff,,I noticed the volume of my pee stream was much greater than ever...That stuff really works!

 

[99yam40]

Re: 1997 DT 225 over heating issue?

Re: 1997 DT 225 over heating issue?

You can pull and test the temperature switches/ sensors to make sure they operate like the should.
If they do then they are telling you that you have a real overtemp. From what you have said you have some cooling passage blockage problems. you should not get 220ish readings around the sensors