1989 225 looper overheating

[midflajim]

Both water pumps replaced along with factory sensors and themostats. Inspection at the thermostat housing showed little salt build up. The engine in question has good water stream at cowling discharge and the temperature rises to 160 (appx). Under acceleration the water temperature rises to 180 (4000 rpm) and the water stream at the cowling discharge is reduced substantially. The temperature returns to 160 below 2000rpm. Any help would be appreciated

 

[andy6374]

Re: 1989 225 looper overheating

Have you checked the pressure relief valve and/or it's spring?

 

[midflajim]

Re: 1989 225 looper overheating

Can you be more specific, mine has a flow control valve attached to the throttle

 

[TxShorty]

Re: 1989 225 looper overheating

If you pull the heads and inspect for buildup, you might find a vent hole plugged in the bottom of the water jacket. Also a vent in the bottom of the water cavity under the regulator/rectifier.

 

[midflajim]

Re: 1989 225 looper overheating

Would I be able to determine if pulling off the heads is necessary if I use a infrared thermometer to measure the temp of each cylinder

 

[MCM]

Re: 1989 225 looper overheating

Determining whether your motor is in fact overheating or you have a problem with a faulty gauge or sensor etc. is a logical step in the troubleshooting process, an infrared thermometer would help would help in determining whether the problem is electrical or internal in nature IMO.

 

[MCM]

Re: 1989 225 looper overheating

Edit

 

[D5GT]

Re: 1989 225 looper overheating

Originally posted by midflajim:<br /> Both water pumps replaced along with factory sensors and themostats.

Little off topic: where you find 2 waterpumps? I'v replased only on impeller... should I be worried?!? or did I misunderstood something?

 

[midflajim]

Re: 1989 225 looper overheating

I have twin 225 hp and use the characteristics of to eliminate problems on the other. Still have not found over heating problem. Head temperatures are within 5 degrees of each other (at spark plug)Water discharge on over heating engine take longer (about 15 sec )than other, Trying to avoid tear down

 

[Solittle]

Re: 1989 225 looper overheating

Did you use the infared thermo to verify temp?<br /><br />If so + your observations in your 12/26 point to an obstruction of some sort. Pulling the heads is not a great big deal & is not a tear down.

 

[midflajim]

Re: 1989 225 looper overheating

Yes used infrared, temp @ 3000 rpm were between 155 and 160 degrees on all cylinders above 3000 is where the problem starts. You are right its not a tear down but if I have to separate the block from the adapter to check the gasket and run into seased bolt problems then its a problem. Do I repower or keep pouring in money. Thats why I want to determine if the problem is on the inflow or out flow side, either its is not sucking enough or the out flow is blocked. I want to and identify the problem not start on a part replacement guess to fix.<br />Thanks for your input hope to get more