suzuki df 115 2001 four stroke heat prob

[welshwarrior]

have obtained a boat and engine which is 2001 and was running sweet till it developed an overheating fault so serviced it and took out the thermostsat.

pumps water really well, and runs for 5 miles and more then alarm sounds saying temp high, engine goes into safe mode. switch off key and restart and runs for another few miles ok then it starts again, now if this was overheating it would not surely run for 5 to 6 miles would it.

[boats.net]

Probably need to replace water pump.

[welshwarrior]

Water pump?

It pumps water great. But do you mean it is not pumping enough ? Thus needing new pump

[welshwarrior]

engine serviced but still fault

It pumps water great. But do you mean it is not pumping enough ? Thus needing new pump

all parts changed casing chambers flushed out power washed and salt away flushed oil changed sensors changed and now it is still saying its overheating this takes either a few mins or 15 miles at sea before alarm sounds and temp light is lit one long beep is the code any ideas guys????

[bucknut32]

I have a 02 DT 225 2 stroke that did the same thing. Found out there was an issue with volts from the sensor to the computer. Suzuki made an inline resistor from block sensor to computer. That solved my problem. Not sure if the 4 strokes are the same but just thought I would chime in because I had the same exact problem. Good luck

[welshwarrior]

cheers will look into it

[noelm007]

First thing you need to do it make sure it is over heating, and not just a false alarm, a simple ,but not exactly scientific method , is to wait untill the alarm sounds, then remove the cowling and feel the engine by hand, are you sure it is an over heat alarm?

[Harper]

I agree with noelm....I'd be suspecting one of the sensors. The overheat alarm can be activated either by the water temp sensor or the exhaust gas temperature sensor.

[welshwarrior]

all new sensors and serviced in full

ok did all changes and now it overheats in 20 secs of starting but checked water pumping ok and found exhaust pressure comming up the hose towards the thermostat now this is not right is it ?????????????

[boashna]

try cleaning the exhaust manifold sensor with a sand paper get the black stuff off . if you have a owner manual book and voltmeter remove it and drop it in a hot boiling water to check for change when it is cold or hot . when the engine gets hot for real it will be making additional noise it will clatter and you can hear the valves.

[welshwarrior]

ok

cheers will give that a go but where is the exhaust pressure comming from that blows up the hose