D17 Series III - Gas in Engine Oil?

Recently, I have noticed that it didn't have much power under load, especially if the engine wasn't warm, but didn't think too much of it until I noticed that I'm getting gas mixed into the engine oil! This just started happening over the winter and this spring.

Any time the engine is running, gas can be seen leaking from the manifold, down the side of the block, especially from cylinder # 4. The exhaust manifold also appears to be "wet" in spots up to the muffler clamp.

I always shut off the gas manually at the sediment bowl and I have checked the carb float and it does indeed "float" when the float bowl is full of gas.

I cannot find any specs or adjustment info for this Marvel Schebler TSX-871 carb, except for idle and load adjustment - nothing about float level adjustment (Is it even possible?) I've heard of bending the hinge on the float, but there is no visible gap between the needle and the float when it is "floating".

Should I just change the needle and seat? I don't know how to tell if mine are ok or not...

Any advice you can offer would be greatly appreciated. If you know where I can find pictures of this carb online, please let me know, so I have something to compare mine to.

Thanks,
Wayne

Yes, I was smelling gas in the oil (on the dipstick) and also when I drained the crankcase, it smelled like gas and was very thin. My rad level never dropped throughout this ordeal.

Now I need help with setting up the idle and load adjustments on my Marvel Schebler TSX-871 carburetor... Anyone have any tips? I have tried adjusting in both directions until the engine loses power, but the engine does not seem to run smoothly anywhere in between. I checked the timing and it seems ok.

Anyone have any ideas?