Is this normal for a 4 stroke?

[RangerGuy]

I probably should just start trusting this motor LOL!..

 

I've always heard how yamaha's don't smoke. So when I saw this I got a little worried. We were up on the West Arm for Thanksgiving and ran about 5-10mins full out. When I stopped to start fishing while the motor was idling I notices it was smoking.

 

I'm wondering if it was just because it was cold out or should this raise concern? The smoke was white/grey it had no

blue colouring like when you are burning oil.

 

Here's a video.

 

http://www.youtube.com/watch?v=Z9As4EW6LeY

 

Other than this it performed really well, this was our first full weekend of fishing in the new boat and we had a full crew. My wife, sister-in-law, 2 65lbs labs and myself. Also all the fishing gear and batteres,. I don't think I could be happier with this boat It never felt crowded with 3 adults and 2 dogs.

 

We had probably a dozen 5 mile runs at wide open. Did some back trolling when the wind kicked up. Fished Saturday, Sunday & Monday and only burned 3/4 of a 19 US Gallon tank. I lost only 1 mph of the top speed when I'm alone. We had 3 adults, 2 65lbs dogs and all fishing gear and still got 35.2 mph as our top speed!

 

This motor seems to be burning even less gas now, I'm just hoping the smoke in the video is due to air /water temp not something

off with the outboard

Edited October 10, 2012 by RangerGuy

[lew]

I've been running my 150 for 3 years now Greg and have never had any smoke coming from it.

[RangerGuy]

That's what I've always heard... it has me concerned!

 

I know I was very careful with the break in, followed the procedure exactly as the manual instructed.

 

Less than 20 hours on the motor, if something is wrong I will not be very happy

[Rob]

That's what I've always heard... it has me concerned!

 

I know I was very careful with the break in, followed the procedure exactly as the manual instructed.

 

Well when the air temperature is cooler than the temperature of the exhaust then you get condensation. Looks to me it's running perfectly. Look at your car or truck on a cool morning and see if condensation is coming from the exhaust. Completely normal.

 

Rob C

[Sinker]

Yep, totally normal for a cool fall day. Its exaust...its hotter than the air. Kinda like your breath when its cold. Nothing to worry about whatsoever!

 

S.

[RangerGuy]

Maybe the 75's run hotter than the 150's maybe that's why I see the exhaust and Lew doesn't.

 

My wife did smell some minor exhaust for a second or 2 but that was the only time all weekend.

[GbayGiant]

100% Normal.

[lew]

Maybe the 75's run hotter than the 150's maybe that's why I see the exhaust and Lew doesn't.

 

I DO see my exhaust on cool mornings Greg, I was just saying that I had never had any smoke from the motor. Guess I should learn to express myself better

[RangerGuy]

OH GOOD! LOL! Thanks for clear'n that

 

Yes.. I'm a bit of a worry wart HAHA!

[aplumma]

Most likely normal but I run two strokes so I can't say. A quick compression test would put your mind at ease as far the condition of your piston and rings from the break in procedure.

 

 

Art

[Crazy Ivan]

Normal. It's warm, not hot. My 75 does the same thing when I run for a while at cruising speed, when I stop the exhaust is warmer than the air, - condensation. Nothing to worry about.

If you really want to baby your motor, let it idle for a minute after a run so it can cool down before you shut it off.

8 years now with my Yamaha 75 4 stroke and no issues.

[mukluk]

My 50 hp. 4-stroke Yamaha behaves the same when the temp. drops. It's 15 years old and still runs like new. Just condensation.

[Moosebunk]

Pretty sure in the cold my 60 has done it too.

[mike rousseau]

I'm thinking steam/condensation is more likely then smoke.... Mine does the same on cold days... Then stops once its warm out.....

[DanD]

Older motors were 100% exhausted out the prop, in other words all the exhaust went out below the water line; there’s nothing to see other then the oil film from an older 2 stroke. Many of the motors now (and maybe just the 4 strokes?) have a small exhaust port above the water line, allowing something like 10% of the engine’s exhaust to exit there. It’s to help promote easier/faster starts with little or no exhaust back pressure during cranking. What you’re likely seeing is the steam from this small exhaust port; which on a cold day is normal. Now if the water pump’s tell tail stream was hot and steaming there might be an overheating issue with the motor. The water coming out of the pee hole should only be warm to the touch not hot to burn.

 

Dan.

[bobkayla]

my 4stroke merc does the exact same thing in cooler temps,,,nothing to worry about

[DaveMc]

My 115 4stroke merc will do the same on a cool or cold day.

[RangerGuy]

Awesome! Thank you everyone for putting me at ease!

 

Like I said before I tend to need equipement to prove it self before I trust it. I gotta feel'n this motor is gonna be a good one

 

I certainly like the performace and mileage.

[fishindevil]

my brand new 50hp yamaha four stroke tiller does the same thing its hot exhaust and no issues my merc four stroke did the same thing....no worries run it ...