John Deere B(1949)

The only thing holding the gravity feed fuel back is a little needle valve seat in the float bowl. If the float is sticky, or has a leak or the valve seat has the smallest of crud on it, or needle misaligned, the gas will get through.

As it slowly gets through, it goes in the carb throat, into the rocker arm/valve cover, and through any valve that is partly open into one or both cylinders.

Then, through the rings it will go, trickling slowly into your crankcase until the fuel tank is dry. So if you run the tractor every day, you may not notice it, but after a week or so, the cumulitive effect will surprise you when you have miraculously "made oil".

You need to fix the carb. And you need to get into the habit of shutting the fuel off at the tank every time.....assuming the shut off works well.....which should also be checked.

Drain the oil/filter and start fresh....the tractor will be fine.

As for remedies, if your proble, is indeed bad rings there is but one remedy: replace the rings. And since this is a fairly complicated operation, you may as well do a complete rebuild while you're at it. A pain in the neck, I know, but you'll likely never have to do it again...

Good luck to you, and thanks for keeping the old iron running!