
03/09/09, 01:53 PM
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Join Date: Jan 2005
Location: NC
Posts: 622
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I'm thinking that one of the piston rings got stuck over the winter and it is allowing compression to enter the crankcase. Crankcase vapors are vented through a tube to the carbeurator where they are drawn in and burned, rather than releasing them to the atmosphere (because those vapors are bad for the ozone).
A stuck ring may produce sufficient volume and turbulence of air inside the crankcase to be pushing crankcase oil through the tube to the carb, where it is then drawn in and burned.
As a diagnostic, either:
pull the hose leading from the carb to the intake and see if it has a lot of oil in it and then start the engine to see if it is spurting oil or, if that is too difficult to do (because the tube is difficult to access),
remove the oil fill cap, start the engine and feel how much air is coming out. (On a new engine, it is close to none, on a worn out engine there is a noticeable puff of air with each compression stroke of the engine. On an engine with a stuck ring, it'll be even more.)
Anyhow, with either the hose removed or the oil cap off, let the engine run for half a minute or more to see if the smoking tapers off and stops because it is no longer feeding oil to the carb through the vent tube.
If there is a lot of air/oil coming out the hose or the oil fill cap, then there is most likely a stuck ring (or less likely a cracked piston). There are several ways of trying to get the ring unstuck that don't involve opening up the engine. I have listed them below. the first ones are the gentlest and safest, the later ones are more risky.
1. pour penetrating oil in the spark plug oil and let it sit for a few days,
2. add marvel mystery oil to the crankcase and the fuel and let it idle for a while,
3. work the engine hard,
4. carefully drizzle a little water in the carb while it is running (the steam may either knock the ring loose or it may break the rod, so do that one at your own risk)
If none of that works, pulling out the piston and carefully freeing the ring by hand/checking for cracks isn't typically all that difficult, so you could consider tacking it yourself.
That's about all I can think of.
ray
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