Dave Harmon

Jeff....what Al has mentioned so far has been good advice but I thought I whould chime in here with some of my experience.

You never mentioned what plug your are using....it must be an OS-F.
If you don't have one I would get one before you go any further.

So far....it sounds to me like the idle and transition mixture is too rich.....this also can be caused by a too cold/wrong/bad plug.
You can verify this by leaving the glow driver connected while attempting to adjust the low speed mixture.
It can be easier to adjust the mixture by observing how it operates during the transition and temporarily ignoring the idle mixture....ie...adjust the transition for best response without getting too lean.

I had trouble with the regulator housing.....I had a drip that would occasionally happen and the idle would change occasionally.
The fix was.....I removed the housing and took it apart and looked closely in the passage that the plunger goes through.
That passage had some machineing debris trapped in the passage causing the plunger to drag and make the mixture weird.
These chips were 'glued' in there by some process YS uses. I poked them out and ran a right sized drill bit through there carefully by hand...then flushed and blown.

The throttle barrel has a similar problem.
Remove the barrel from the carb housing and look very carefully at the fine slot in the center of the length of the barrel.
That slot has been known to have metal chips 'glued' in there and also is a crap trap. You can make sure it is absolutely clean by dragging a razor blade through it and closely inspecting the slot with a jewelers loupe.

Closely inspect the carb gasket....the engine is old enough to still have the brown paper gaskets that get mushy around the passages.
Replace all gaskets with the newer, better quality black gaskets available from YS PartsandService.

The regulator plunger (Central Hobby part 48 YSE0176) has been a particular problem for me on several engines.
You can inspect this part with the loupe.....what happens is this part is cut off a mold tree by a worker with sharp cutters.
Sometimes they get sloppy and nick the plunger in the area where it seats....this causes the drip from the intake and also can mess up the idle and transition idle.
This leak almost never affects full throttle because the leak is not enough to affect the large amount of fuel going through at full throttle.....but a small fuel leak here at idle may put the mixture out of range of the adjustments.
Also....there is usually a 'bead' of left over mold flash around the circumference of the plunger that is not trimmed off. This might also cause the plunger to not seat properly or hang up so it will not open and close rapidly according to the crank case pressure pulses.

Also....you have not mentioned what fuel you are using.....it must be at least 20% nitro and no less than 18% oil.....no castor in 4 strokes.

That wet sound at idle is pretty normal.....these engines have a slight slurping sound at idle.

Try to use a test stand when trouble shooting the engine....it is a lot easier than in an airplane.
Make sure the engine runs dry. Clean the engine with alcohol or lacquor thinner/acetone and then run the engine looking for fuel leaks.
Gaskets and O-rings leak in both directions....they leak fuel or oil and can suck air as well.
Both will mess up the mixture.....especially on the carb casket and backplate casket.

Remove the needle socket (part 55) and inspect for trash in the carb housing....remove needle valve and inspect in there too.
I have had problems caused by small chips of fuel line that got in there and caused huge problems....the fuel line chips are almost invisible....they are almost transparent.
Flush and blow in both directions.Flush all new fuel tubing before use to get rid of the silicone chips.

This is getting too long so try all this and let us know how you are doing.