I just picked up a used Midwest Cherokee and the guy said it had a Enya 50 ringed. It turns over like tar on a cold day. The question of the day is “What’s a good way to bring back a ringed engine”. At the moment I’ am think of popping the glow plug and flushing with glow fuel an go… but will that make sure the ring is freed up.
Thanks Rich

Glo fuel should work. If the castor is only congealed enough to make it stiff then that should work. It can harden to become stuck, in that case glo fuel would work to unstick it but would have to soak. Just be sure it is freed enought that the bearings and all other parts are smooth. Shouldn't take much to do it.

Motor oil will not cut the goo.

Be sure and take Sport Pilot's advice.

If you do not get it real free, the balls will skid in the bearings and cause problems for you.

I'll soak it for a couple days in Sig 10% champion make sure it’s in the crankcase. Are you saying the ring is not the issue as much as a stuck ball bearing that may skid. Can you feel this or must I remove the cowl, engine and back plate and look. Or am I just getting paranoid.
Rich

Correct. A stuck ring may cause some loss of compression for a while, but will cause no real damage. A ring should become unstuck in just a few minutes of running. In your case it sounds like the oil is not completly congealed, so both bearings and ring should be OK without a long soak. If it feels smooth it should be OK, this would mean any balls have disolved or become soft enough that they would not be a problem.

you could pour some marvel mystery oil in the carb and turn it over a few times. This will help dissolve the castor goo.

All you have to do is squirt some fuel into the cylinder and down the carb and turn it until it loosens up.

Castor oil and petroleum oil do not mix. That is why we do not use mineral oil, even the two stroke variety in our fuel. However methanol, which is what our glow fuel is, readily dissolves and thins castor oil. So MMO will not dissolve congealed castor oil. Glow fuel will.

Marvel Mystery oil mixes quite nicely with glow fuel. I just mixed some 50/50 with glow fuel to make sure. That's why I use it as an after run oil.

To free the ring, invert the engine then fill the cylinder with enough methanol or acetone to get what would normally be a hydraulic lock. Move the piston through that lock and it'll force the methanol into the ring groove a bit at a time to dissolve the gummed castor. The movement of the piston will cause the ring to drag on the cylinder wall and get the methanol onto both sides of the ring. Just soaking usually won't be enough because the methanol won't be able to get past the gummy barrier. The ring is free when you look through the exhaust and can see a tiny bit of free play at the top and bottom of the ring in the groove when the piston is moved very slightly.

If the ring is gummed then the bearings will be gummed as well so they have to be freed up too. This can be done either with a bit of heat initially then flood with fuel or just flood with fuel and work them until the methanol dissolves it. When it feels free give it a full tank of fuel but running as rich as possible so there's a lot of fuel inside to flush out any stubborn undissolved bits as they come free. Personally though, with bearings I prefer to remove them to make certain they're free because it doesn't take much to make the balls sticky enough to start skidding and that's when the damage starts.

Thanks guys you convinced me to stop the urge to just fly it . I’ll take it out and soak the crap out of it then do my normal inspection before bench run. This is typically the new engine way but after all said an done it is new to me been a long time since I had to adjust an air bleed carb anyway. Yea downunder I run them rich on break in too.
Thanks Rich.