John Deere B smoking/blowing oil

[MarkMac77]

I have a 1948 JD-B, it sat in a yard for a decade. I resurrected it with a new carb, new ignition, spark plugs, and other parts. The engine had collected a fair amount of rain water over the years. I changed out all the lube. It only ran on a single cylinder for the first few hours, and then the other came alive.

She smokes pretty badly and blows oil droplets out the exhaust stack. There is an intermittent engine rattle that accompanies heavier puffs of smoke. It sounds like a penny bouncing around inside the cylinder. I suspected maybe pitting on the cylinder bore from rain water running down the exhaust, or maybe a damaged piston ring.

I did a compression check on the advice of the forum, and she did surprisingly well. 140# on the right and 130# on the left side.

This is how she sounds:

https://youtube.com/shorts/uHmBPgXWxDY?feature=share

Droplets of oil spray everywhere from the exhaust stack.

How is oil migrating from the crankcase and out the stack with apparently good compression? Is it sneaking through the valve train somehow?

 

[MarkMac77]

Also, I expected the amazon compression tester to be full of oil, but it was clean. The oil doesnt appear to be migrating past rhe rings.

Maybe the rattle is a broken valve spring? Would that cause oil to be expelled out the exhaust? Would it still have good compression? Its a lot of oil escaping.

 

[Mark-Ia]

Bad ventilator pump in the fanshaft will pump oil.

 

[MarkMac77]

I rebuilt that whole shaft. Maybe I fouled up. There is oil slowly dripping out the front, at the alternator pulley.

 

[Mike(NEOhio)]

Maybe the oil rings are shot?

 

[Leroy]

There is a vent return line going if I remember correctly to the govener housing, if clouged it would force any blowby out that fan shaft and take oil with it. Did you make syre that lne was clear? Never had a problem with that ventlator pump on the tractors I had 49 B, 50 AR & 51 A. The earlier 38 A & 46 B tractors did not have that closed system for the crankcase but just a venterlator cap so no pump.

 

[MarkMac77]

Ill check today.

I REALLY appreciate the guidance.

 

[IAfarmguy]

This may be way off the mark. Are you sure the oil you are seeing from exhaust isnt coolant? Like from a bad head gasket? Have you looked in the top of radiator while the engine is running? Turbulence in coolant from compression leak would indicate a problem.

 

[Lee B]

I had that episode quite a while back there now where I saw drops of motor oil on the hood and assumed everything except what it really was.

It could be oil not being returned to the crankcase by having it idle with the clutch engaged which usually means for long periods of idling, putting the brakes on, the transmission into neutral and engaging the clutch to allow the belt pulley to turn. This causes right main bearing oil spun into the reduction gear cover to be returned to the crankcase by design. Clutch disengaged it just builds up in that cover to a level that can't all fit at once back thru the finger sized hole for that purpose and it then overflows into the clutch and gets spun out everywhere by the belt pulley.

And this is why when you see old timers in a parade driving these things they will pull it out of gear and engage the clutch when they have to wait more than a minute or two in stopped traffic. They don't like wearing motor oil and that's the only way to avoid it with a letter series tractor.