I got conned into checking my neighbor's 1997 Johnson 2-stroke, 115 HP Ocean Runner. It starts right away but runs rough and spits oil out the exhaust as witnessed by my no longer white vinyl fence. It has gotten almost no use in years so I'd expect smoky exhaust but this is spitting oil. Changing plugs and fuel filters helped just a little as far as running goes. Compression is OK, 135 on all cylinders. Any ideas?
Oil in 2-stroke exhaust
- Thread starter bls-fla
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The oil in the exhaust is because there is oil in the combustion chamber because it's a 2-stroke. A 2-stroke, by design, combines fuel and oil in the combustion chamber. Also 2-strokes often run rough when not actually in the water. Try with it in the water (or a big garbage can/tub) and see if it's any different. You didn't mention if the gas is also a couple years old?
I know there will be oil in the exhaust; I've had Evinrudes and Yamahas and none of them spit out this much oil. However, you could be right about trying it in the water. I don't know about running it in a tank, as I say, there's a lot of oil coming out so I don't know if I should recirculate it. As far as the fuel goes, I have added new clean fuel but I've wondered about that myself. I think before I put it in the water I'll try to run it from a small external tank. Thanks for your response.
It's hard to say from this side of a computer screen "how much is too much", you know? You'll have to be the judge of that. If it only ran for a few minutes, and not for a long time now, it could be just that - run it longer and get it up to operating temp for a while. It could also mean that the oil injection system is out of adjustment, dumping too much oil in. Of course, that's assuming it has an oil injection system - I'm not sure on that. If it's using pre-mix, then it might be as simple as too much pre-mix. Or maybe someone ALSO pre-mixed, along with the injection system... possibly as a winterization procedure... but we're back to guessing without having more information.
That would be one of my first steps, too. It at least gets rid of some variables.
bls-fla said:
That would be one of my first steps, too. It at least gets rid of some variables.
Lt.Mike
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2 Stroke motors really pass quite a lot of oil.
If it's a premix or injected it won't seem like a lot until you see it accumulated on or in something as in this case, your fence. I used a trash can to quietly flush my Mariner 25 hp ob and was shocked at the quantity of oil coating the trash can. Made me a believer on 4 strokes being better for the environment, though both my boats are still powered by 2 strokes.
You know if that motor was fogged before storage there is a heavy sticky film of oil throughout that engine that will take awhile to clear out. That will exaggerate the amount of oil the engine kicks out.
Incidentally, the Suzuki owners manual for 2 stroke engines recommends running a 50:1 premix along with the injection for the first tank of the season. I can tell you first hand that the oil discharge and smoke is noticeable. :roll:
Mike
If it's a premix or injected it won't seem like a lot until you see it accumulated on or in something as in this case, your fence. I used a trash can to quietly flush my Mariner 25 hp ob and was shocked at the quantity of oil coating the trash can. Made me a believer on 4 strokes being better for the environment, though both my boats are still powered by 2 strokes.
You know if that motor was fogged before storage there is a heavy sticky film of oil throughout that engine that will take awhile to clear out. That will exaggerate the amount of oil the engine kicks out.
Incidentally, the Suzuki owners manual for 2 stroke engines recommends running a 50:1 premix along with the injection for the first tank of the season. I can tell you first hand that the oil discharge and smoke is noticeable. :roll:
Mike
Along the lines of what Mike is saying about "accumulating"... I don't know about you guys, but when I spill a couple teasponfulls of oil on my garage floor, it sure as heck looks more like a quart!
I'm trying to brainstorm this until I get to the boat again. I don't claim to be a 2-stroke expert but I've had a few and I've run them from the earmuffs, believe me, this is too much oil in the exhaust. Yes, it has the oil injection system. I did check the oil in the tank, I can't vouch for the quality of the oil but it does look clean and there's no sludge or crap in the tank. Obviously I've been all over the map on this but I keep coming back to the oil in the exhaust. I once thought it wasn't burning all the oil in the cylinder/cylinders because it was running poorly. Now I'm almost convinced that too much oil in the cylinder/cylinders is causing it to run poorly. I'm sure there's a way to check/adjust the gas/oil ratio (50:1 desired) but as of yet I don't know how to do that. I have seen several posts about swapping out the injection system for pre mix on this motor so it must be a problem. I do appreciate all the input, guys.
Let me ask you this... and again, I'm on the other side of a computer so I can't see things... have you ever run a 2-stroke close to a white fence before? It might be hard to really make a comparison based strictly on the white fence. I can absolutely see a 2-stroke dirtying up a white fence like someone flicking a paintbrush at it.
I don't know the Johnson oil injection system - but the Yamaha actually adjusts the amount of oil based on RPM. I think at idle, it cuts it down to something like 100:1. So IF there is indeed too much oil being thrown in, then see if you can't find the specs for making the adjustment.
I don't know the Johnson oil injection system - but the Yamaha actually adjusts the amount of oil based on RPM. I think at idle, it cuts it down to something like 100:1. So IF there is indeed too much oil being thrown in, then see if you can't find the specs for making the adjustment.
No, I've never actually run a 2-stroke next to a white fence before. And you can bet your bottom dollar I never will again. But I have run my Yamahas and I have walked behind the motors while running. I wouldn't do that with this motor.
Lt.Mike
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I trailer both my boats and flush both after each use in salt water.
Walking behind them you might see the oil film on the water run off.
One other thing to note is that both motors drip oil out of the exhaust, down the prop and skeg while they are stored on the trailer.
If you ask me using a little more oil isn't a problem.
You just run a little smoky.
Using too little oil...oh ya, now that's a problem.
That'll net you a dead motor.
Mike.
Walking behind them you might see the oil film on the water run off.
One other thing to note is that both motors drip oil out of the exhaust, down the prop and skeg while they are stored on the trailer.
If you ask me using a little more oil isn't a problem.
You just run a little smoky.
Using too little oil...oh ya, now that's a problem.
That'll net you a dead motor.
Mike.
Everything you say is true. I could walk behind my Yamahas while running; this Johnson ruined my white vinyl fence in minutes. I let it go for a while but it didn't get better. It's not just smoke, it's spitting a lot of oil. Just thinking about it gives me a headache. I might just have to take it to someone who can actually diagnose what is happening.
Lt.Mike
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I gave the Johnson a look up and confirmed that that model is still carbureted.bls-fla said:
Your Yamahas are probably fuel injected and you really can't compare one to the other particularly in respect to the emissions. The Johnson is probably going to be rich and have a "generous" 50:1 ratio while the Yamaha will run lean and inject as much as half the oil as the older motors.
I really wouldn't sweat the Johnson running dirty. It is what it is and it still gets the job done.
I fire my older 2 smoke Suzuki at the dock and chuckle as the guys with the newer 4 strokes belly ache about the smoke. Later on the water they can't keep up and my motor broke my bank at $2,250.00.
Sure theirs gets better mpg but I figure costing some $12,000 more mines still way cheaper to run.
Can't justify the newer cleaner motor yet.
I'll bet your neighbor will run that Johnson for years to come.
Mike
To wrap this up I took the boat to a local mechanic I trust and my suspicions were confirmed. The motor was running rough because there was a bunch of crud in the exhaust, since the exhaust was somewhat blocked the engine ran rough, couldn't burn the oil, and spit it out. The crud consisted of bugs, dirt, etc which got there because the boat sits there mostly ignored. So again the old advice to use the boat holds true. Thanks for all the input.