Smoking Exhaust

[G.S.G.]

I am now getting time to work on my IH 330 project tractor, and this is a follow post from several months back. Compression check showed, #1-cylinder 130 cold & 140 hot, # 2 100 C & 125 H, # 3 135 C & 130 H, #4 140 C & 145 H. As recommended earlier, I did adjust the valves. Tractor starts but smokes a lot. There is a black oily substance coming from short exhaust pipe. Carburetor has only one adjustment screw and doesnt have any effect on engine when it is turned in or out. I suspect carburetor is my problem but would like your thought before I spend $250 on a new one. Thanks in advance. I will try to send Pic.

 

[wore out]

You can have sticking, worn or broken oil control rings and still have good compression.

I suspect that's at least part of your problem.

 

[jimtrs]

(quoted from post at 14:09:45 11/13/22) Compression check showed, #1-cylinder 130 cold & 140 hot, # 2 100 C & 125 H, # 3 135 C & 130 H, #4 140 C & 145 H

ot sure the cold compression numbers are of much use. When possible, compression testing on an engine that is warm from running is better.
That being said, you numbers seem too high, except for cylinder 2, which is almost 30% lower than your highest. That's too much. All should be within 10% of each other.

WAG from you saying later

Tractor starts but smokes a lot. There is a black oily substance coming from short exhaust pipe

is the oil rings have failed (broken, frozen, stuck, etc.)
That could give higher compression numbers, and certainly smoky and oily exhaust.

Carburetor has only one adjustment screw and doesnt have any effect on engine when it is turned in or out. I suspect carburetor is my problem but would like your thought before I spend $250 on a new one

y thoughts on buying a new carburetor - is don't. Sounds like your carburetor may just need a good thorough cleanning.
Dont know what carburetor you have, but with only one adjusting screw, (other than idle speed) this is most likely for the idle jet. Usally adjusts air for this jet. These idle passageways are very small and easily clog up, causing no change in carburetor idle adjustment.

If you're thinking your running rich causing black at the exhaust, this would usually be sooty dry black, not oily. A carburetor without an adjusting screw for the main jet, would not usually run rich, unless you're missing the main jet or have some other damage to the carburetor. Non-adjustble main jet carburetors will much more often run lean, from being clogged, than run rich.

If you got a zenith carburetor (sounds like it), and it actually does need to be replaced, you may want to go with the Marvel Schebler TSX-748 version for your tractor. That should have an adjustable main jet.

 

[gene bender]

just let the carb alone nothing wrong with it you need rings or seals on the valvestems

 

[fastfarmall]

Dont waste money on a new carbruetor, you need rings or valve work!

 

[G.S.G.]

Thanks for your responses. I will now tear into the engine.

 

[used red MN]

Is there any chance the breather on top the valve cover is plugged completely? This may cause the rings to pass more oil than normal due to be high crankcase pressure. Especially if the tractor sat a lot recently or was not worked real hard. Long shot but better than an unnecessary overhaul. I am surprised Old has not chimed in; I would believe that his normal ATF soak treatment might help this engine. Pull the plugs and put 2-3 tablespoons of automatic transmission fluid in each one and let it set a week. Then it would be best is it could be worked fairly hard an hour or two just to see how it plays out. Only reason I say all this is because his compression numbers look good.

 

[rustred]

If it was mine I would get it under a good loose and work it hard for a few hrs hot but not boiling. Even if u have to cover the grill. Monitor the oil on dip stick. From full till when u stop it by checking it cold each time. See if it is using oil. All it might need is the workout to seat the rings. Plus u did not say how the plugs look or if they are all the same color or if any have more carbon build up than the other one. Important to read your spark plugs , they tell u a story.

 

[caterpillar guy]

First that looks more like the vent tube at the bottom of the engine from the block or tappet cover. Not the actual exhaust pipe from the exhaust manifold. different things with different issues. His is blow by and all engines have some, and some more than others. Now it can be from a multitude of things worn valve guides,tired oil rings,even high amounts of idling can effect that as excess gas to the cylinders can washout the rings causing some extra blow by, then an engine that has set unused for several years or one the rings never got seated correctly,and on and on. The cylinder that is low I would check for tight clearances on the valves first. Then go work it's tail off for a day or 2 then recheck for excessive oil blow by at the vent tube you show. Might get better might get worse. I would check all these things out before tearing into expensive engine work.

 

[JIM MN]

2X what- wore out- stated.. Also, tractor is spitting unburnt-burnt oil and smoke..