smoke out of crank casae breather of cub cadet 127

Malchren · Apr 20, 2012

bought a 1967 cub cadet 127 that had been sitting for god knows how long. had no compression and trans relief valves where stuck which i fixed. any way no to the pressing mater, i got it running good and have had it running for around 4 hours now but the smoke that is coming out of the crank case breather is still puffing out like a freight train. does anyone know what can cause this and how to fix this. i am going to rebuild it and soup it up a little to help when mowing in the heavy grass. will replacing the valve guides, valves, piston, rod, and have the block bored out and valves seats cut fix this problem? i appreciate all the help.

Oldtractorfixer · Apr 21, 2012

You probably have a stuck ring. the work you are planning will definately fix it.

Malchren · Apr 21, 2012

Yes but then wouldnt it burn oil out the exhuast if it was a stuck ring? I do appreciate the help though. Just waiting till i get paid and the 106 is up to snuff before i go tearing into it.

Oldtractorfixer · Apr 22, 2012

If the oil ring is working but a compression ring is not you can get crankcase pressure (puffing on a single cylinder) but oil is being controlled on cylinder wall so not excessive out the exhaust. I would expect a broken or more likely stuck second compression ring. The top ring would more give you low compression. That's the theory anyway. I suppose there may be another way to get puffing from some other route of compression to the crankcase but I can't think of any. Maybe a broken piston or something.
Those are tough engines. You will likely not find much cylinder wear.

Malchren · Apr 23, 2012

The compression ring is what seems most likely cause it runs and starts beautifully. Hopefully i will be able to rebuild i soon just waiting on parts. Should be fun. Thanks for all the help, i appreciate it.

RandyT · Apr 23, 2012

If this is one of the old cast iron block single cylinder kohler k-series, make sure you get new head bolts otherwise you will be blowing heads gaskets about 15 minutes after it is started up and then will not run again until the engine cools down.