TO-30 Smokes

My tractor has started smoking when it is idling but when I rev it up it clears . When it's under power such as bush-hogging, it smokes more
when it's going downhill or when it's going sideways on a hill.Get back on level ground and it clears. Also when it's smoking it starts to
miss. Does this sound like valve seals?

What color smoke?

If it's black smoke, and from the symptoms you describe, sounds like it's running too rich.

Is the outside of the carb wet with gas? Dripping gas with the engine off and fuel valve open?

If so, the float may have a hole in it, partially sunk. Or the needle seat is loose, bad, or float out of adjustment, trash in the needle/seat. Any of these things will cause the fuel level in the carb to be too high, aggravated by being on unlevel surface. The problem is worse at idle because the fuel is being used at a lesser rate than it is entering the carb bowl. Once under power the level is drawn down to a more normal level.

The carb is simple to rebuild. Best fix the one you have than replacing it with aftermarket.

Might want to take a look at the condition of the fuel tank. If it is shedding rust into the fuel line, the carb will be contaminated again. Be sure the screen is in the sediment bowl.

Another commonly overlooked item is the air filter mesh, up inside the housing above the oil bowl. it needs to be pulled out and cleaned periodically.

If The carb is flooding, there is a possibility the engine oil is contaminated with gas. This can raise the oil level and cause blue smoke, oil leaks, low oil pressure .

Those engines are not prone to smoke excessively because of worn valve guides. Very little oil makes it up top, just enough to lube the rockers.

It.s blue smoke and it'll just about choke you to death when your at a low idle and trying to hook up an implement, but when I rev it up a little it clears right up.

Typically, oil smoke is blue in color, but it is not real offensive, just an oily smell and long lasting fog.

Raw gas can have a white color to it, and be very noxious, eye burning, smell like gasoline. Raw gas can pass through the engine as a result of low compression. Leaking rings, bad piston, burned, stuck, leaking valves, severely blown head gasket. A compression test will reveal the condition of the engine.

Also lack of spark can cause it. Check your point gap, side play in the distributor shaft, general condition of the plugs, points and condenser, coil, wires, cap and rotor.

If nothing else, take a plug reading.

Normal plugs will have a tan color insulator.

If all are gloss black with grainy carbon deposits, they are oil fouled. If only one has this appearance, there is a problem with that cylinder.

Powdery black indicates too rich fuel mix.

If one or 2 are washed clean, wet with gas, indicates no spark or no compression.