2014 Merc 90 EFI 4-Stroke Runs 10 minutes then quits

[Baur]

Launched boat for first time this year, went maybe 1000 yards at slow speed before motor sputtered and quit, would not restart. Had no issues last year or since I've had boat and motor. Took to dealer for repair, massive amount of water in fuel, engine oil milky according to mechanic. Fuel tank drained, engine oil changed, last update is motor starts, runs for 10-15 minutes idling before quitting. Any thoughts or comments would be appreciated.

 

[alldodge]

Howdy

What does the oil look like now?

 

[Texasmark]

Fuel tank vent working ok or is it clogged?

 

[Baur]

Thanks for responses, boat still in shop so not sure what oil looks like now after changing and running for short periods of time. In regard to fuel vent, motor quit after same time frame with external fuel tank attached so that would eliminate vent on tank in boat. Does anyone know if there is something electronic that would cause motor to quit after a period of time? Sensors, etc.?

 

[alldodge]

Water in the fuel, if fuel pump isn't pumping and others would stop the motor. After it stops can you restart right away or what does it take to get it to restart?

Also when water was in the oil, was the water in the leg or the motor?

 

[Baur]

Will need to ask tomorrow as to where oil was, as for restarting I could not initially I assume because of water in fuel. At the shop, they changed filters, changed oil and ran with their fuel source. What I don't know is, if after draining boats fuel tank, did they run it with fresh fuel in boat tank and it shut off after several minutes or were they hooked to their fuel source and it ran for several minutes before shutting off.

 

[Baur]

Pontoon boat with permanent 35 gallon tank, can I assume there is a vent somewhere on tank?

 

[Johark53]

Usually water in the oil is not a good sign!! Somehow water must be getting into the crank head gasket could be sipping water in the oil. While running does the motor seem like she's heating up that may cause her to cut out

 

[Texasmark]

Pontoon boat with permanent 35 gallon tank, can I assume there is a vent somewhere on tank?

I smell bad gas due to age or moisture accumulation. 35 gallons smells like not much fuel gets used per outing. Toon smells of sitting in the water for long periods of time unused.......condensation on that one, especially when you are around the water where lots of moist air is present. Can't assume on the vent as they can and will get clogged if it has one. Tanks of that size will usually have 3 holes: Fill hole, vent hole, gauge flange mounting hole.

If you have a built in deck vent connected to that tank via a rubber hose, probably located adjacent to the fill hole, it should have a screen built into it to keep wasps and such from building a dirt blob nest in it but you can't be sure, and you can't be sure one didn't build a nest on top of the screen sealing off the vent. I know for a fact that bilge pump outlet holes in conventional boats are prime targets for getting plugged.

 

[Faztbullet]

Need to find out when it quits if fuel pump is still running, if not fuel pump needs to be inspected.. Usually if water in fuel injectors will need cleaning as they will clog and stick due to pintle rusting.

 

[Baur]

Update.... Boat has been in shop now for two weeks, fuel tank drained after determining majority of fuel was water, motor was turned over with spark plugs removed and water expelled from cylinders. Oil changed, fresh fuel from external source, motor runs for extended periods of time, oil was milky again from water but not increasing in level (which is a good thing!). Oil changed again, fuel in tank replaced with fresh, motor runs for extended periods of time with oil remaining clean. Picking boat up later this week, will give it a test in water and hope for the best. Technician has recommended that assuming I have no issues that I should change oil again after usage for a couple weeks just as a precaution. Thanks for all the input.

 

[Texasmark]

Glad you got her fixed.