Engine smoke

[Marshall]

Ok everybody, need some advice on this one . My starboard engine ( Sx 232 Limited HO engine non-Calif.)
Runs good, starts good ,idles fine, good rpm, However, after about 3 hours of run time ,some fast some slow
I 'm getting what could be described as black soot coming out the exhaust and coating the areas around the
engine with this "black soot" Same stuff you would see around the front of a fire place. It has a oily feel to it .
The engine exhaust smells to be running very rich . Ok lets have the cure .
thanks ,

 

[Marvin willis]

Are you saying that your getting smoke in the engine compartment?

 

[itsdgm]

When's the last spark plug change?

 

[Scottintexas]

it's not uncommon for you to get a black soot around the exhaust near the jets, usually a plug change helps, not heard of soot around the engine (in the engine compartment).

 

[Andy S]

I have had that happen to me once after a long run of about 6 continuous hours. When I refueled I added some SeaFoam to the fresh tank of gas (I only burn non-ethanol fuel) and subsequent tanks and have never had the problem again. This made me believe I had a partially stuck injector and the SeaFoam helped clear it up.

 

[Marshall]

Thanks guys,
No, there is no smoke in the engine compartment , Just a lot of
black coloring where the exhaust comes out next to the the jet drive.
and it does smell like it is running rich. don't know about spark plugs,
bought it used and I have only put about 20 hours on it . Port engine is fine,
no exhaust trails .

 

[Scottintexas]

since you don't know the history I would suggest changing the plugs, be careful removing number #3 as it can be frozen in place and break off, be sure to use anti seize when you put the new ones in, it's easy and gets you to know the boat better, look in the member tips for a how to with pictures,

until you do use the seafoam as andy suggested, you can get it at walmart or any autostore,

update your profile with your location, if you were close by I'd be glad to help you, maybe there's somebody in your area,

 

[Murf'n'surf]

Change plugs and add Sea Foam.
Sounds like a stuck injector which can lead to major problems if not diagnosed soon. During a run, stop and look at your oil. Smell it also -- smell fuel?

 

[MutherTucker]

This all makes me scratch my head a little. I just changed plugs and oil (marina changed plugs and oil......yamalube...) in June, but also noticed a little black film on the rear end of my vessel this past weekend after having wiped it down from the weekend before (it sits in a fresh water slip.)

Didn't think to check oil or smell for fuel as i know NOTHING about boats and have had mine for just 2 months. I love this forum. I'm learning a lot. Hopefully i learn enough before i kill my boat......

sorry i can't offer a solution as i am not qualified, but you may have just saved my a$$ from a clogged injector or #3 plug. now i just need to figure out how to diagnose and fix without breaking anything I'll start with the seafoam i think. that sounds easy enough.

 

[Scottintexas]

@MutherTucker changing sparks is also very easy, it could be they just gapped one wrong, check the member tips section for a step by step how to with pictures,

On another note I see your location as SHELBYVILLE, IL , is this correct?? did you happen to notice the 26 yamaha boats on Lake Shelbyville two weekends ago?
https://jetboaters.net/threads/shelbyville-illinois-july-30th-to-august-3rd-2014.302/ talk about a close to home get together,

Glad to have you onboard,

 

[Marshall]

Thanks to All for the info,

Talked to 2 different Yamaha service people ,
They both said I had over filled the oil . Oil was all over the
spark arrestors , and had coated the air filter to the point
of saturation ( new one on order ) . Service man said it was overfilled. I did add oil to the
tank , but did not go above the "Full " mark boat sitting level. Service man said it's been over filled.
OK , How does the oil get up to the area of the spark arrestors and all over that area , and soak
the air filter ?? Have removed enough to just a little above the 'ADD' mark. Waiting for the air filter
so I can try again. I agree the oil was being sucked into the engine and burned causing the smoke out the
exhaust and all of the black oily film on the back of the Boat. Has does the oil get into that area ??
thanks again guys ,
hope this cures the problem.

 

[MutherTucker]

@Marshall, i think you have your answer there, i read something about this on "the site that shall not be named" or however that phrase goes....

i had the marina change oil and plugs as this was prior to my joining this (better) forum and i didn't want to do anything myself just yet.

i ran the engines to tool out of my slip and take the boat out of the water for an entirely different issue (busted fuel sender.)

once on the trailer and home safe, i was futsing around in the engine compartment to pretend like i could possibly detect any other issues. i checked the oil and realized the sticks were above the full line. I read the dang manual like a good girl and even i knew that was wrong. oil should be just between low and half full when engines are cold (please hold applause)....so, i put the muther tucker back in slip (like a dum dum who probably shouldn't run engines with too much oil) and requested for the marina to extract oil. They did, but I'm not sure if i have damaged my plugs, filter, yada yada after running it for that short time out of the slip and back. I have had the boat out at least 10 times with no issue.

I will be checking and will post results right in this spot!


i may be dumb, but i have diagnostic cables and software to make me smarter

 

[MutherTucker]

@Scottintexas, yes, i went bonkers when i saw all of those lovely boats pull in!!! i knew nothing of the gathering or this forum, but i felt like a baby duck who had found its mama once i saw everyone! I am one of very few jet boats that i know of who reside on this lake. you bet i will be there next year!

 

[Gym]

Thanks to All for the info,

Talked to 2 different Yamaha service people ,
They both said I had over filled the oil . Oil was all over the
spark arrestors , and had coated the air filter to the point
of saturation ( new one on order ) . Service man said it was overfilled. I did add oil to the
tank , but did not go above the "Full " mark boat sitting level. Service man said it's been over filled.
OK , How does the oil get up to the area of the spark arrestors and all over that area , and soak
the air filter ?? Have removed enough to just a little above the 'ADD' mark. Waiting for the air filter
so I can try again. I agree the oil was being sucked into the engine and burned causing the smoke out the
exhaust and all of the black oily film on the back of the Boat. Has does the oil get into that area ??
thanks again guys ,
hope this cures the problem.

@Marshall. The MR-1 engines you & I have in our boats are pretty tricky when it comes to oil level. When changing oil, never put in more than you extract. You should have oil visible on the stick before starting the engine but it should not be up to the LOW mark. Once you are in the water and properly warm up your engine you can then adjust your oil level to the Full mark.

What happened to you was someone may have filled your cold engine to the Full mark. When the engine warmed up the oil expanded and blew into the air intake soaking your filters. Until you get the new filters you can run the boat without as long as you have cleaned the oil out of the air box. You may find your plugs are fouled also.