Tractionlesscoltgt
Cadet
- Joined
- Apr 11, 2019
- Messages
- 8
I have a 115 4 stroke mercury that is stuck in limp mode will not rev past 3100 rpm. It is also making oil at this point. So far I have looked into the thermostat as that seems to be a common problem being stuck open that is not the case here. Mine is closed was put in boiling water to test and see if it opened as it should everything worked as it should. Next I thought thermosensor but I do not know if the sensor is testable I hooked my multimeter to it and could not get a reading I tried reading it in progressively warmer water and cold water no readings on either was attempting to check ohms. I decided to try and run the motor in the driveway with muffs for about 30 minutes I could not get temps at head above 120 and at thermostat housing was only seeing about 114. I quickly undid the thermostat housing to see if it was open after running for the 30 minutes and it was still closed! I know the engine is in some sort of cold start enrichment state that I can not get it out of. So i feel the culprit is either the tstat (but I'm having a hard time with that seeing how it functioned properly when progressively warmed up from fully closed to fully open) or the thermosensor (but I do not know what resistances I need or if that sensor even works that way?) unless I am overlooking something else that is related. I changed spark plugs last night pulled the old ones they were black as night. Pulled the new ones today they are black as night from trolling for about 2 hours and motoring across the lake to drift fish. Is there a way to pull the engine diagnostic codes? I have seen a video of a different type of engine that the fellow was able to put the ecm into service mode and use a test light to read the beeps based on long flashes and short flashes. Anyways any advice is greatly appreciated.