Vermeer SC252 with Honda GX690 engine smokes profusely when under a load

[hoping and praying]

Lately I have noticed my Honda powered Vermeer SC252 smoking profusely when under a load. I only put non-ethanol fuel in it, and sometimes add 'sea-foam' to the fuel. I was grinding some stumps today and when it would get under a load, it would start running really ****** by misting and significantly dropping in RPM's along with smoking like crazy. I asked a friend who is also a very reputable mechanic and he said that if it were the rings it would be smoking all the time and then asked if there was too much oil in it, which it was at the correct level when the dipstick was pulled. The engine only has like 220 hours on the hour meter, which I am aware could be bogus (I purchased it second hand a few months ago).. The engine is a Honda GX690, does anyone know what could be wrong? What do I do? Any input is and will be much appreciated, thank you very much for your help. Also a note, I replaced the spark plugs recently, they were black as hell and the gap was nowhere near specs, it was damn near closed and there was a very thin gap...

 

[earlthegoat2]

White smoke?

 

[hoping and praying]

No it is black smoke

 

[Sleepy]

No it is black smoke

Oil smoke is blue and has a distinctive odor to it, black smoke is too much fuel.
I'm thinking you have a carburetor problem. When this engine is doing that, look at the choke. Is it all the way off?

 

[pro94lt]

Is this happening when it's leaning?

 

[hoping and praying]

Sleepy, the only time I turn the choke on is when I crank it, after it is cranked I turn it off, so the choke is off... And pro94Lt, it initially started when it was leaning, for then while scooping the mulch away with a pitchfork, I would raise the grinding wheel, turn the wheel off and pull it away from the stump while getting rid of the excess mulch. I would idle it down to a minimum but the engine would be tilted due to the wheel being at its highest position. Since that day I now turn the wheel off, raise it, drive it away from the pile, idle it down, BUT INSTEAD of leaving the wheel up, I lower it so the engine will be level. The smoking occurrence has happened while engine has been deviated as well as flat.

 

[Sleepy]

Sleepy, the only time I turn the choke on is when I crank it, after it is cranked I turn it off, so the choke is off... And pro94Lt, it initially started when it was leaning, for then while scooping the mulch away with a pitchfork, I would raise the grinding wheel, turn the wheel off and pull it away from the stump while getting rid of the excess mulch. I would idle it down to a minimum but the engine would be tilted due to the wheel being at its highest position. Since that day I now turn the wheel off, raise it, drive it away from the pile, idle it down, BUT INSTEAD of leaving the wheel up, I lower it so the engine will be level. The smoking occurrence has happened while engine has been deviated as well as flat.

Black smoke is fuel related with a 4 stroke. A video of it running would help but based on what I know so far, I would be looking inside the carburetor.
Is the air filter clean?

 

[Mowingman]

Most likely carburetor or electrical ignition problems. I used to own a small engine sales and service shop. The larger, (over 10-12hp), Honda engines are prone to all kinds of problems. Do not spend much money on it, the engine was a problem the day it was built. Ever wonder why the thousands of commercial ZTR mowers you see running, NO NOT have Hondas on them? It is because Honda can not build an air-cooled engine in the 20HP+ range, that is troublefree.
Electrical problems can cause the engine to run rich, thus the black fuel smoke. find a really good small engine shop that knows Honda engines inside and out. They should be able to find and fix your problem. I am betting ignition or Carb.

 

[250R]

When your carburetor float sticks it just dumps fuel into the engine causing black smoke

 

[Chashowlett]

Ya, sounds needle and seat related to me

 

[Chashowlett]

You might need one of those spring loaded off road needles