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Oil inside cowling

T

Terry in Ottawa

Contributing Member
On my Johnson 25hp, J25TEEDA converted to remote, there is always a coating of oil inside the cowling underneath the carburetor.

I suspect that fuel is leaking out of the carburetor when I have the motor tilted up on a transom saver for transportation.

Is this normal? Is there something I can do to prevent it?

I suppose I could always disconnect the fuel line when I've finished boating and allow the carburetor to run dry.

Any other ideas?

Thanks
 
There is a wee hose from bottom of engine to the top bearing area.---Check it for leaks / cracks.-----Oil recirc system it is.
 
Unless your tank is vented which yours is like mine from the pictures you posted and your tank pressure gets high during transportation it will push fuel into your carb and flood engine..I had this happen in the past.Hot days can make it really bad.I leave my hose disconnected now during transport...Not saying that is causing your problem.I have seen threads on this before I believe.
 
Racerone:Is that wee hose part of the manual primer system? I can see a fuel line coming out of the manual primer and going to a "T"; after the "T" one line goes to the primer nipple on the top starboard side of the carburetor and the other line goes to the cylinder block. I hope the attached picture shows some of this detail.

J25TEEDA primer lines-small.jpg

Newyota: I'll try to find out more about excess fuel tank pressure forcing fuel out of the carburetor. This would mean forcing fuel past the check valves in the manual pump on the fuel line coming out of the tank, through the fuel pump on the engine and then into the carburetor. Thanks for the suggestion.
 
The tilt of the engine.... Yeah, that's a problem that's hard to get away from. Many boaters have an assortment of old rags (or new) that they place under and forward of the carburetor just for that accepted "tilt" problem.
 
The ability of the carb to shut off fuel flow is circumvented because the float runs off gravity. You must remove the fuel line from motor.....or tank, when motor is tilted in transport. If you have an original steel OMC fuel tank, the tank is NOT VENTED when the hose is unhooked from the tank end, so it should never be left out in direct sunlight.
 
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I never mentioned hoses from the primer system.----No the wee hose is NOT part of the starting system !----Look for a wee hose from the bottom of the block that goes to the top of the block.-----It is the oil recirculation hose.
 
Terry in Ottawa said:
Racerone:Is that wee hose part of the manual primer system? I can see a fuel line coming out of the manual primer and going to a "T"; after the "T" one line goes to the primer nipple on the top starboard side of the carburetor and the other line goes to the cylinder block. I hope the attached picture shows some of this detail.

View attachment 18669

Newyota: I'll try to find out more about excess fuel tank pressure forcing fuel out of the carburetor. This would mean forcing fuel past the check valves in the manual pump on the fuel line coming out of the tank, through the fuel pump on the engine and then into the carburetor. Thanks for the suggestion.
Click to expand...
It is amazing the pressure in the tank and how it pushes fuel out.I did a test with a spare fuel line fitting just connected to tank like yours by itself in the hot sun.In a matter of a few minutes gas was gushing out due to pressure build up.I do not recall on your tank fiting if there were any little tab type things that get pushed in when putting on your fitting to tank?
 
timguy said:
The ability of the carb to shut off fuel flow is circumvented because the float runs off gravity. You must remove the fuel line from motor.....or tank, when motor is tilted in transport. If you have an original steel OMC fuel tank, the tank is NOT VENTED when the hose is unhooked from the tank end, so it should never be left out in direct sunlight.
Click to expand...
He has an older plastic duratank like the one I have.
 
Racerone: Thanks for the clarification. I'm not near the boat at the moment so I'm relying on memory, old pictures, and MarineEngine parts diagrams to try and identify the wee hose. I'll have a very thorough look when I get back to the boat and see if I can find it and inspect it.

Newyota: I found a very interesting article on this problem of excessive pressure in fuel tanks causing spillage out of the fuel lines. I'll be disconnecting my fuel lines at the tank and the engine from now on. If anyone is interested here's a link to the article: http://archive.jsonline.com/busines...engine-fuel-tanks-b99533059z1-311869641.html/

joereeves:an old rag stuffed under the carb during transportation sounds like a good idea if the spillage is coming from the carburetor. I'll be doing that too.

Thanks to all.
 
Is the item #26, circled in red below, an oil recirculation line? It's not listed in the parts description as such, in fact, it's not listed at all.

J25TEEDA intake manifold.JPG

On pages 2-37 and 2-39 of my service manual there is a reference to an oil recirculation line and shows picture of it going into the intake manifold just below the left-side carburetor mounting stud.

J25TEEDA service manual.jpg
I don't recall ever seeing such a line on my 1996 25hp Johnson but I'll definitely look for it the next time I'm at the boat.
 
You like many others are grasping for straws.---Have a high level of doubt.-----You need to look on the cylinder block page of the parts manuals and the hose is shown there .----Absolutely no doubt about it !!-----It is shown on 1976 model to 2005 models of that engine block.
 
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Terry in Ottawa said:
Is the item #26, circled in red below, an oil recirculation line? It's not listed in the parts description as such, in fact, it's not listed at all.

View attachment 18674

On pages 2-37 and 2-39 of my service manual there is a reference to an oil recirculation line and shows picture of it going into the intake manifold just below the left-side carburetor mounting stud.

View attachment 18673
I don't recall ever seeing such a line on my 1996 25hp Johnson but I'll definitely look for it the next time I'm at the boat.
Click to expand...
Look on the cylinder and crankcase parts page..You should see it there.It runs vertically from bottom to top of crank case intake side.
 
Still have the original oil recirc hose on my 1956 5.5 horsepower. That's when they made good stuff. I have 7 cd12's. Only one of them had to be replaced. They may crack right at the end where they bend at the nipple that enters the bearing/bushing area.
 
I feel like I'm walking through a forest looking for trees, right in front of me but I'm not seeing them.

I've gone and looked at the Crankcase and Cylinder parts diagrams and may have found the elusive oil recirculation line. I've circled it in the picture. There's no reference to it in the parts list and no parts number.

J25TEEDA crankcase.JPG
 
Are you still denying the fact that hose does exist on your motor ?----The hose in the circle of red is on your motor !!----Most dealers have that on a 50' roll.
 
Sorry racerone. My boat and motor is 100KM away from me right now and I can't physically inspect the motor. I will the next time I go to the lake. In the meantime, I believe that it exists, you and timguy, are very convincing on that. I was just looking at parts diagrams to find it.

Thanks for your help and your patience.
 
Its there but your not there to find it, they can rot off especially with ethanol spilling out the carb. Do you use ethanol? This is just a misunderstanding, we are sorry too. I have seen ethanol/oil disolve rubber in the matter of weeks. It is very destructive to most older....pre 2010.....outboards. Much of the work that I get here at my home based shop in Northern MN, is ethanol related. I can't imagine how expensive it is where you live. OUCH! I spend time at our resorts in NW Ontario and everything is so expensive in Canada, just don't know how you can afford it. I haul fuel across from the US. By the way, that hose can be bought also at your auto parts store. Use a good quality zip tie at nipples.
 
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timguy:The motor was 11 years old when I bought it and I would expect it was running on ethanol based fuel to that point. Since then I have mostly been running high octane, ethanol free, gasoline. If I expect to use the fuel within 30 days sometimes I'll buy the lower octane that does have ethanol.

I'm beginning to think I should be running high octane 100% of the time and avoid the possibility of ethanol related problems.

Thanks for sharing your experience.
 
I’m at the boat this weekend and have had no luck finding that oil recirculation line.

I’m concentrating on the intake side of the crankcase looking for a small line going from the bottom to the top. If it has rotted away I don’t see a hole or a fitting where a line would attach to.

When I’m looking down the throat of the carburetor I’m expecting to see that line on the left side running from bottom to top. Am I looking in the wrong spot?
 
Look straight back behind on where your roller rides for your throttle linkage rides on the cam.You should see where it connects to the engine.It then travels down behind possibly where your wire terminal block(asumming you have electric start) is then down to wrap around the lower area of intake and hooked up down there.Thats how my 1985 20hp is with rope start.
 
Finally found the oil recirculating line and it looks to be OK. Hard to tell though since the top is buried under the flywheel and the bottom is hidden under the starter motor. And everything being black on black didn’t help.

Thanks to Newyota for isolating this for me and thanks to everyone for their patience
 
I rarely have to replace these hoses. The "old timers" were copper tubes. That's just the way things were engineered way back when I was a kid. The copper was the way to go, but the rubber composition on the newer motors did hold up well until they "shoved" ethanol down our throats. If you measure the performance loss when using a lower grade of ethanol laced fuel versus 100% 91 petrol, the extra cost is almost worth it.....probably gain back about 60 to 70 percent of the extra cost. When the motor is really loaded down, your recovery is a higher percentage than when trolling. The real benefit of pure non oxy is the protection of seals, o-rings, needle valve tips, VRO's, water pump impeller, hoses, and the main factor of all is fuel longevity. Ethanol fuel will suspend the alcohols weight in water/moisture. That is what destabilizes the fuel, eventually separating the ethanol and water mix, then reducing octane as the foul mix settles to the bottom. Stabil will slow the process, but still it will happen.......and it will be over a 6 to 7 month storage time in damp climates.
 
Copper may have been the way to go because there was no synthetic rubber.-----I often ask folks about material for a parachute in the mid 1940's----They often say " nylon " of course.------then I say silk , simply because folks " do not know " the facts.
 
So very true. Back then rubber was different too. At my remote camp in NW Ontario I modified 2 4wd trucks and dragged them 30 miles through the bush to be used over a mile long portage road. I put used tires on them. That was 1982. They are still perfect with not a single flat in 36 years. They are using different rubber today. My 1956 cd12 5.5 has the original impeller, pumps as good as a new motor yet. These new impellers today are often bad in a few years. What's going on?
 
A disposable era.----Price matters and durability does not.----Just picked up a 2008 model 115 E-TEC for interest and to dissect .----Deemed not economically repairable by dealer.
 
Always trying to learn too, but my interest is waining with this newer stuff. Like the wife's Dodge Caliber. ADP......? What is it? Alternator decoupler pulley. Yup. Gonna soon be a WAP. .....Yes, you guessed it. Welded alternator pulley. 85 bucks for another destined failure, or a few inches of wire off the ol' mig. The choice was easy for me. Alternators been used in cars since 1964 and now they decided to try putting a 1 way clutch on 'em. For what? To save mileage? You gotta be kidding me......Detroit, or wherever that engineer is.
 
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