JD model B white vapor from around clutch

[Jim Skala]

When running slow with a few misses, I see a white vapor coming from around the clutch. I also see this if I am running fast and shut down by deactivating the magneto -- I see lots of it then. I don't smell anything in the vapor (white smoke that dissipates in air). I'm wondering if it could be fuel vapor that got into the crankcase. Does this indicate that the seal between the crankcase and the clutch is blown? It is possible that the crankcase vent back to the air intake is plugged?
 

[bigboreG]

Could possibly be moisture in oil? Does the tractor sit quite a bit? What year is it by the way? Sounds like its building crankcase pressure and if its too old to have a ventilator pump, then the engine is probably worn, and the stuff your seeing is blowby. My '42 B had blowby, a good hone and a set of new rings cured that. I also did a valve job and rebuilt the carb at the same time.
 

[Lee B]

There is no seal to blow or replace between engine and clutch opening. If you don't smell gas it's not fuel - it has to be water. It's more likely that you are making so much water vapor as to overload any ventilation scheme the tractor is using. But the vent could be plugged too, what's it cost to check?