Smoking cub update

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1948CUB
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Re: Smoking cub update

Postby 1948CUB » Sun Mar 06, 2016 6:15 pm

Thanks for the reply.

I just looked at the front spark plug and I have oil. It cranks and runs good -- the compression check was also good.
With the compression being good where could the oil be coming from? I left the plug a little loose and its blowing some
oil around the plug. Again the engine runs great. I'm confused.

Danny

Eugene
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Re: Smoking cub update

Postby Eugene » Sun Mar 06, 2016 8:09 pm

1948CUB wrote:With the compression being good where could the oil be coming from?
Crankcase oil is bypassing, not being whipped from the cylinder walls by the piston's oil control ring. Either the oil control rings are completely plugged up or worn out.

I would continue the SeaFoam treatment and see what happens. Worst thing is that if the Sea Foam doesn't loosen up the oil control rings, the engine needs an overhaul.
I have an excuse. CRS.

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Glen
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Re: Smoking cub update

Postby Glen » Sun Mar 06, 2016 8:14 pm

Hi,
It sounds like the oil rings on the pistons are either stuck or wornout. They have to be free moving in the piston grooves to expand and work, if they are stuck or wornout, the engine will smoke. That's why the guys use oil additives, to try to get the rings free. If they won't free up, or are wornout, they and the other rings need replacing, or the engine might need reboring to bigger size pistons.
The other rings, compression rings, can be not stuck, or not as wornout and the engine will still have good compression and power.
Here is a page from the Cub parts book showing a piston and rings. The oil ring is number 5 in the pic. :) :tractor:

http://www.farmallcub.info/manuals/cub_ ... 012-04.jpg

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Re: Smoking cub update

Postby international 274 » Mon Mar 07, 2016 8:09 am

Danny I am in Tuscaloosa, I sent you a PM.

Matt Kirsch
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Re: Smoking cub update

Postby Matt Kirsch » Mon Mar 07, 2016 9:54 am

Put the Seafoam in from the top if you aren't already.

What's worked best for me is to get the engine warm, then spray seafoam into the intake with an old windex bottle, as much as the engine will take without killing it. Probably 1/4 of a can is plenty in a small engine like the Cub. Once you get it in there, shut it down and leave it overnight, or a week. Next time you start it up you will know what REAL smoke is, but it should clear up after a while. If it's going to work, that's the best chance it has.

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Don McCombs
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Re: Smoking cub update

Postby Don McCombs » Mon Mar 07, 2016 11:59 am

Matt Kirsch wrote:What's worked best for me is to get the engine warm, then spray seafoam into the intake with an old windex bottle, as much as the engine will take without killing it.

The company that makes Seafoam, packages it in a spray can. It's called Deep Creep.
Don McCombs
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DZG
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Re: Smoking cub update

Postby DZG » Wed Mar 09, 2016 10:42 pm

Oil in the exhaust is a good thing, lubes the valves lol.

Its odd the oil is not getting burned off during combustion, and is coming out the pipe as oil, not blue smoke.

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Re: Smoking cub update

Postby Puffie40 » Thu Mar 10, 2016 12:09 am

That's because the oil in the exhaust is not completely burned, but a lot of it is vaporised instead. The oil vapor will collect on the walls of the exhaust pipe and condense.

Two strokes motorcycles have a similar issue with their exhaust pipes, and diesel engines will have similar grime around their cylinder heads if the engine is not worked very hard.

Oil droplets spewing out the pipe usually means worn out valve guides and maybe even scored valve shafts on a overhead valve engine. I'm not entirely sure if oil can easily get up the valves in a flathead engine.

1948CUB
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Re: Smoking cub update

Postby 1948CUB » Mon Mar 14, 2016 5:38 pm

Hi folks,

Well today I removed the plugs and sprayed WD-40 in all the cylinders. ( a pretty good amount ) I let it soak
most of the day and turned over the engine several times during the soaking period. I changed the engine oil
from 30W to 10W 30. Had a hard time getting it started the first time but fired up and smoked like a tire burning
for a few minutes then started to clear up. The bad smoking I had before is almost cleared up. It is only puffing a
small amount under load now. The problem of oil spots on the draw bar has stopped. I'm going to put the break plow
back on the tractor and give it a real test. I will let you know what happens. ( garden is too wet to plow now )

Danny

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Re: Smoking cub update

Postby TurboRoadster » Mon Mar 14, 2016 9:16 pm

cool


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