Heavy smoke and Oil in air filter area

chieffan

chieffan

Tractorologist
Member
Have no idea how long it has been since this old L Head B&S has been run. No fire, points were junk so went with the new armature CDI system. Got fire. Bench ran the engine a bit, ran good. Put it in the GT, ran it a couple 3 times for a min or two. This morning started it up to verify I had the wiring tight and it started smoking heavy. Was hard to start too. Had give it s hot of gas in the carb and it fired right off then. Now I have a bunch of oil in the base of the filter housing. Oil level is right on the full mark with fresh 30W oil. Never ran into this before so not sure where to start looking for the problem. Any/all suggestions welcome and appreciated.

Engine model: 401417 Type is 0145 01 Built in March of '81
 
I don't know if they used the reed type breather on those but if they did it might be stuck in the closed position.
 
Has separate breather for each cylinder. Tube from each runs up to the air filter box. Pulled the snowblower off the IH 1650 and put a deck under it this afternoon so I can at least mow. The 1650 has a late model Vanguard 16 hp in it so it will handle the load OK. Plan no is to pull that engine again, put new head gaskets in and check both breather filters and se what is going on. What I don't understand is the engine ran good 3 or 4 times for short periods each time with no problem. Then this morning right after it started the smoke started bellowing. Thanks for the suggestions, falls in line with other information I have read.
 
Decided to find out exactly where the oil was coming from. Removed the air cleaner, breather tubes and air tube from the flywheel. It started right off, ran it about 1/2 throttle. After about 30 seconds oil started gushing up out of the breather tube vent hole. Facing the flywheel it would be the right hand cylinder side. Now I know where, but to figure out why ? ?
 
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That should be #1 cylinder. Why? I can't answer that!
 
chieffan said:
Decided to find out exactly where the oil was coming from. Removed the air cleaner, breather tubes and air tube from the flywheel. It started right off, ran it about 1/2 throttle. After about 30 seconds oil started gushing up out of the breather tube vent hole. Facing the flywheel it would be the right hand cylinder side. Now I know where, but to figure out why ? ?
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make sure the oil is not mixed with gas. I run across faulty needle and seats causing gas in the cylinder which runs back into the crankcase and cause issues like that.
 
First thing I checked. Oil was changed and it is still right on the full mark. No indication of fuel in the oil. I run fuel shut offs on all my tractors for that reason but a good point to bring up. I learned that the hard way when the dip stick blew out of an Onan.
 
KennyP said:
That should be #1 cylinder. Why? I can't answer that!
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Right on Kenny, #1 cylinder. The fact that oil is coming through that filter it sure is not plugged. But I wonder about the other one to equalize pressure? Kind of like a noise in a vehcile. Look at the opposite end it sound like it is coming from. Time to put it back on the bench and find out.
 
This is only a guess. Could it be possible the oil ring is stuck in the cylinder and the compression rings not stuck.

Noel
 
Could be as this engine had not run for some time. It was in a tractor, all together hood on but think it was outside. Being horizontal opposed hard to get anthing up around the piston to soak those rings. This last time it did not smoke as the oil was not getting into the carb to burn. My thinking is it is more of a pressure issue in the crankcase or vent filter but not sure.
 
After over 2 hours of mowing this afternoon I got back to the old L head Briggs. Found one of the vent valves stuck shut, but not the one pumping oil out. The one pumping oil out had a piece missing from the gasket. Cleaned everything up in the parts washer and hung them out in the breeze and sunshine, occasionally, while I mowed. Made a new gasket & put the vents back on, intake and tubes on the vents. Fired it up on the bench and ran it about 3/4 throttle. Had fumes from the vent tubes but no oil. Hope I found the problem. It goes back in the tractor in the morning.
 
If one was stuck shut the other would be pumping oil. I'm guessing it was a reed type vent.
Nice you found the problem and it wasn't an expensive fix.
 
Yes Chris they are the reed type vents.

Motor back in the tractor, everything hooked up. Fired it up, ran it for 10 min or so about 3/4 throttle while I cleaned the bet pulley on the PTO. Put the air filter on and cover, started to put the top on and it started slowing down. Pulled the filter and it run OK. Figured I got to much oil that new Fram filter. Left the filter off and drove it down to the machine shed to take a filter off another engine I know is good. Put that filter on, then the cover and shortly it started to die again. Lifted the cover off & it ran good. Started back up to the shop and got about 20 feet from the shop and the smoke started rolling and oil started flying, (Had the top on w/o out filter & cover). Shut it off - had about 1/2 cup of oil in the base of the air filter. That is just plain stupid. This is not a pressurized system. Got to be a reason but what is it ? ? Could the timing be off enough to still have it run but building pressure in the crankcase ? ?
 
Going to leave it till later some time. Think I will pull the engine again, Drain the oil out and fill both cylinders with diesel. and let it sit for a few days and see what happens. Sure can't hurt anything. Might loosen up any ring problem it may have.
 
Man oh man those kinds of things can drive a sane man nuts. There has to be a reason that crankcase is building pressure like that and I don't think it's the rings. More inclined to think the breather is stuck again. What happens if you leave the filler tube opened a little?
 
Haven't tried that yet Chris. One more thing to try for sure. It starts right off, never turning more than on revolution before it is running so I think it has good compression. I drove it about 250 yds before it started to smoke hard and blow oil. Before that just light fumes. Just had the air cleaner base on with the tubes hooked up as it would not run with a filter on. This also could point to a faulty breather valve.

After I think about it, before it started the smoking and oil puking bit both vent tube were venting light fumes, so if there is a breather valve that is causing the problem it is intermitant - and which one? The oil always comes from the #1 breather vent. So #1 could be stuck open or #2 is stuck shut.
 
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I tried leaving the filler tube open with the gas line holding it off to the side engou so the tube was open. Started it up, ran abou 1/3 throttle & in about 10-15 seconds the oil started flying and the dip stick was sucked over the tube. Lost that round too. Can get the #2 breather but the #1 is NLA anywhere. 495756 is the part number. Old number is 393153.
 
Just another guess here. Could there be to much oil in it. Could the dip stick be wrong.

Noel
 
Oil is right below the full mark now that it has threw a bunch out. Put in 1.5 qt when I filled and brought it right to the full mark. In these old engine that been around the block a few times it is hard to tell what modifications may have fell on them. I have two others that run good to kind of fall back on to compare if things don't look right. Your on the right track Noel , at this point it is a guessing game.
 
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