MR1 engine overheating only when underway.

[305SX230]

Hi everyone, I could use some advice. I have an 04 SX230 with the MR1 engines. About 2 months back, I took the boat out, and the starboard motor overheated. I looked over, and water was coming out of both of the spouts at the same rate. When I got home, I ran it on the hole, and it would not overheat. I clamped off the hose headed into the motor, and connected the hose to flush the intake. I ran it again, and it still overheated. I pulled the thermostat and found it was in bad shape. I replaced the thermostat and cleaned the housing, but it's still overheating. I also ran the YSD 2.0 software, and all sensors read as functional. I'm I missing something? Before I pull the motor out and check all the water Paths and valves, can you guys think of anything? All most forgot to mention it also does not overheated if idling in a body of water.

 

[FSH 210 Sport]

Hi everyone, I could use some advice. I have an 04 SX230 with the MR1 engines. About 2 months back, I took the boat out, and the starboard motor overheated. I looked over, and water was coming out of both of the spouts at the same rate. When I got home, I ran it on the hole, and it would not overheat. I clamped off the hose headed into the motor, and connected the hose to flush the intake. I ran it again, and it still overheated. I pulled the thermostat and found it was in bad shape. I replaced the thermostat and cleaned the housing, but it's still overheating. I also ran the YSD 2.0 software, and all sensors read as functional. I'm I missing something? Before I pull the motor out and check all the water Paths and valves, can you guys think of anything? All most forgot to mention it also does not overheated if idling in a body of water.

Do you boat in fresh or salt water?

 

[305SX230]

Salt water

 

[Scottintexas]

did the YDS store the over heat code ?
did you run the YDS in real time to monitor the temps ?

doesn't your boat have 4 indicator lines on the hull, do all four lines throw water while at speed ?

my first thought would be to run the YDS to get real time data,
then get a infrared thermometer and check the temps between both engines at different spots and don't forget the exhaust,



have you watched the video of how the cooling water flows, it gives good insight,

buckbuck mr1 cooling water - Google Search

 

[Captaindaddy]

I had a really hard time diagnosing an overheat issue on my 04’ AR230. Confirm this for your boat but on mine once the over heat warning light comes on it stays on until the motor is shut down and restarted. So I would suck in some debris at low speed and then blow it out when I throttled up but the light would still be on even though the hull lines were flowing water and no other indicators that the engines were hot. Drove me crazy, hope your issue is this simple, it’s at least worth a shot to cycle the keys and make sure you’re getting current engine temp info.