Yamaha F150 blowing white smoke

[MikePA]

(2017 with 51 hrs) Curious if anyone knows what's going on here. My boat has been sitting idle for 3 weeks, had the oil changed yesterday, was going to take it out today, when I put the boat in the water and turned on the engine it was blowing white smoke I let it idle for 10 minutes and it continued to blow the smoke. I turned it off and ran it again, it continued to blow white smoke, I tried that a couple more times and then called it quits, fearing something going wrong. I took it home and ran it under the muffs at home and it was not blowing any white smoke anymore..

 

[Lucky Streak]

Maybe the place you had the oil changed fogged the motor thinking winter storage?

 

[MikePA]

Maybe the place you had the oil changed fogged the motor thinking winter storage?

Good thought but it was a mobile guy and I was there so I know he didn't.

 

[Tightlines22]

White smoke often indicates blown head gasket. Hard to believe with such a new motor though.

 

[ReelSlim]

I read something about white smoke can be caused by oil getting past your rings if it’s stored all the way down when not in use especially if it’s over filled. Try leaving it stored slightly tilted up. I’m doubting the head gasket unless you had issues before the oil change.

 

[ReelSlim]

https://www.google.com/url?sa=t&sou...lowing-smoke&usg=AOvVaw2Lu1-O2FymAlWM2-Iq9deZ

 

[walleyes]

https://www.google.com/url?sa=t&source=web&cd=&ved=2ahUKEwi63o_qp-DsAhWUITQIHeeRBvUQFjAAegQIHxAB&url=https://www.yamahaoutboardparts.com/forum/general-discussion/yamaha-outboard-forum/16868-yamaha-f150-blowing-smoke&usg=AOvVaw2Lu1-O2FymAlWM2-Iq9deZ

Oil will be blue smoke not white, white is water.

The article you posted talks about blue smoke RS.

But good heads up on the storing an engine slightly tilted. What people’s thoughts on this. I’m a little new to 4 stroke engines and have only stored them 1 winter prior to this one.

 

[ReelSlim]

Yeah wrong link. I’ll find the one that I had read about white smoke. Blue is definitely oil...lol

 

[Sea Chaser]

White = water I agree

 

[MikePA]

Wonder how that much water got in it, in 3 weeks with it stored under cover?

 

[ericl]

Read something on THT about water getting into O/B combustion chambers by putting the engine into reverse while still moving forward at speed. Dunno if water in fuel could cause this?

 

[gungadin]

Do you flush your engines after salt water use? Could be stuck thermostat, or coolant passages. When oil was changed, was it milkey. If you still have the oild filter, pour it iut to check. Water in fuel could also cause it, but you shold of had a warning light or buzzer sound at the fuel filter under the cowl. you might also want to remove any zincs, in the block to make sure they are still in one piece.

 

[noluck]

do a compression test first, use a remote start or ground the coils, throttle wide open

 

[profisher]

Too much of a coincidence that an oil change was done and right away you have smoke. Check plugs just to make sure...if water is getting into a cylinder the plug will look washed or very clean from the steam produced. If they are all the same check oil level in crankcase and then run it at idle on the hose for a longer period of time to burn off any excess oils in the cylinders.

 

[MikePA]

Thanks guys. I do flush after every use, I bought it with 30 hours on it, so not sure how he took care of it. None of the oil had any water in it when it was drained. I'm pretty sure I have a stuck thermostat as The Telltale never comes up to temperature, and water comes out the exhaust, would this cause the white smoke? I took it for a spin this morning for an hour and a half and it ran fine. And it's weird, it only smokes when I run it in the water, whenever I run it on the muffs there's no smoke or water from the exhaust.

 

[profisher]

If you are running early morning when its cold out it could just be steam from the cold morning air and warm water from engjne. No steam later in the day on the hose when the temp is warmer maybe? Easy to check t-stat...it would be stuck closed to produce steam as the engine would run hotter. You haven’t mentioned any alarms going off so I’m leaning to just cold morning temps causing it.

 

[MikePA]

If you are running early morning when its cold out it could just be steam from the cold morning air and warm water from engjne. No steam later in the day on the hose when the temp is warmer maybe? Easy to check t-stat...it would be stuck closed to produce steam as the engine would run hotter. You haven’t mentioned any alarms going off so I’m leaning to just cold morning temps causing it.

I was hoping that was the answer, so I waited for someone with a Yamaha 115 next to me to start up and they didn't have any white exhaust.

 

[Ringo]

I was hoping that was the answer, so I waited for someone with a Yamaha 115 next to me to start up and they didn't have any white exhaust.

I wouldn’t loose hope yet. Your engine is almost brand new and has a higher compression,meaning there’s more condensation and which can take longer to burn off. If it’s performing normal and there’s no alarm, I would just check the oil level before each trip.
Do you remember what type of oil your mechanic used last time. I find newer engines are more sensitive to oil viscosity so maybe use the recommended oil from the manual for your next oil change? I had a new Honda yeas ago that would only start cold and perform well on 5W30M in the winter.

 

[MikePA]

I wouldn’t loose hope yet. Your engine is almost brand new and has a higher compression,meaning there’s more condensation and which can take longer to burn off. If it’s performing normal and there’s no alarm, I would just check the oil level before each trip.
Do you remember what type of oil your mechanic used last time. I find newer engines are more sensitive to oil viscosity so maybe use the recommended oil from the manual for your next oil change? I had a new Honda yeas ago that would only start cold and perform well on 5W30M in the winter.

Ok interesting. I went and bought yamalube from the dealer.

 

[MikePA]

Pulled the thermostat off and put it in a pot and heated the water.. it opened up. Wonder why water is coming out exhaust when in the water then? I'll get the mechanic to do a compression test. Can an engine still run really well with a head gasket leak?