IH CC 112 Kohler 12HP engine runs rough, why?
 

I have a cub cadet 112 or 100. The engine runs rough, it sat in the garage for a year. Starts fine. Lots shaking and black smoke from the exhaust. There is no choke on this (I cant find one). Oil level did not change over the last yr as it sat in the garage (so it's not burning or leaking oil?) See this video to listen to the sound and see the shaking, difficult to see the black smoke because it was evening and not too bright outside. What's causing these symptoms and what can I do to help get the engine to run more smoothly and not cause as much black smoke? Is there a choke on this model? Thank you!! Looking forward to your comments. https://www.youtube.com/watch?v=tEOnWiXjybE

In the video I can see that the choke plate is closed.
You may need to reach in behind the air filter plate under the sediment bowl and open the choke.

IH never made a 112 model. Looks like someone jammed a 12HP into a 100.

From the video I saw, looks like a major tune up and Carb works needs to be done.

The second post it spot on, the choke butterfly is closed.
Might be a good idea to hook it to the choke cable so it can be controlled when needed for starting by the operator from the seat without removing
the air cleaner.:beerchug:

The tractor seems to be an IH Cub Cadet 122.
Agree with previous posters.....choke is close.
There should be something on the side of carb towards the rear to open the choke.

Thank you very much.
This would explain why it would backfire sometimes, too rich a fuel mixture, right?

I can see no choke cable at all and it looks like a bolt head in maybe what was the hole for the choke control knob.

There is no cable for the choke, like Merk said, it was behind the carb, easy to find.. looks like a cable could have been attached at some point, has a hole in it... I dont think it's a manual choke because its not easy to access it if the filter was on.. I will attach a cable. Meanwhile, when I opened the choke the engine kept dying...

I heard that if you run an engine with the choke closed for a while you damage it and then it never runs well with the choke open <- any truth to this?

Meanwhile, while idling, (i did not touch it) this happened https://www.youtube.com/watch?v=dGfwPqbjSlM The engine sped up on its own and then popping and flames came from the exhaust. This was ysetday while the choke was still closed! It also ran out of gas... so the gas was low.

What makes the flames shoot out the exhaust... the choke and fuel mixture?

When you began to run out of gas, the engine started to run lean which causes it to backfire and speed up. You should be fine once you refill. Unless you got some dirt and sediment down the fuel line when the tank drained out.... it happens sometimes when you run out.

Now that you understand the choke had been closed, how does it run with it open? It might be possible you might need to do some tuning.