2009 SX210 Overheat warning

[ACO175FO]

I'll start this by saying I checked as many engine overheat threads on here and still can't figure out my problem.

Last weekend I pulled away from the dock in no wake mode, went for about 5-10 minutes and the engine overheat light came back on. I returned to the dock immediately and shut it down. I waiting 10-15 minutes for it to cool down, then started up and ran the throttle up a few times figuring I sucked something up. Headed out again and overheat came back on. Took it out of the water checked for anything blocking the intake, did not see anything obvious. It was peeing water out of the ports on the side of the boat.

At home I pulled the thermostat from the engine. Ran the engine without the thermostat and the overheat light came on in about 10 minutes on the hose. I did check the thermostat in a pot of water on the stove, it opened up at about 150-160 degrees. I bought the Yamaha diagnostic software and ran it until the overheat warning came on. The YDS gave a code 252 overheat warning.

No idea where I go from here. Some say change the spark plugs, I will try that tomorrow. Anything else I should be looking for?

 

[Scottintexas]

I wouldn’t think spark plugs

Have you watched buckbucks video in the faq section about how cooling water flows??

I’m thinking cooling passage blockage in block or exhaust

maybe get infrared thermometer and shoot it at different points on each engine to compare temps

 

[Scottintexas]

How long have you owned the boat?
How many hours on the engine?
Do you normally flush?

 

[ACO175FO]

Have you watched buckbucks video in the faq section about how cooling water flows??
I’m thinking cooling passage blockage in block or exhaust
maybe get infrared thermometer and shoot it at different points on each engine to compare temps

Yes I have watched the video on cooling water flow. I don't think anything is blocked, but I guess my last resort would be to pull the exhaust and check. I will try the thermometer.

How long have you owned the boat?
How many hours on the engine?
Do you normally flush?

I have owned it two years now. YDS says 186 hours on each engine. I flush it every time I use it. It is used primarily on salt water.

 

[Scottintexas]

It could also be a bad sensor

I would compare temps and if no obvious hot spots I might consider a sensor problem

 

[Cobra Jet Steering LLC]

Yamaha had a history of bad heat sensors back when your boat was made

 

[ACO175FO]

It could also be a bad sensor
I would compare temps and if no obvious hot spots I might consider a sensor problem

I thought about that, but the YDS software says temperature sensor normal.

 

[WREKS]

Yes I have watched the video on cooling water flow. I don't think anything is blocked, but I guess my last resort would be to pull the exhaust and check. I will try the thermometer.


Reply:
If the cooling water jacket surrounding the cylinders is plugged, pulling the exhaust will not reveal the problem. Shine the block as Scott advised to find a/the possible hot spots.

 

[ACO175FO]

Haven't had time to mess with my boat for a few months. I finally got a chance today to try to diagnose my overheat issue. In the process I replaced the anodes on both engines, and they were both pretty bad looking. I also got an infrared thermometer to check engine temps. I found that the area around cylinders 1 & 2 on the exhaust manifold side got up to above 200 degrees within 3 minutes running on the hose. Overheat light came on within 5 minutes. At this point I am assuming the cooling jackets are clogged. I read the thread on the closed loop flush method, but it might be a bit above my skill level. Are there any other options for me besides taking this to a mechanic for a full engine overhaul?

 

[Brad_Ct]

Unfortunately this is probably what you have built up in your water jackets. I did the acid flush twice and still had this blockage when I took the engine apart.

 

[ACO175FO]

View attachment 210661
Unfortunately this is probably what you have built up in your water jackets. I did the acid flush twice and still had this blockage when I took the engine apart.

Yeah I think that is going to be the case. I dropped it off with a mechanic. He estimated $1500 per engine to pull them and clean out the water jackets.