C175 and 417A running weird once warm

[AHS 1,482]

The C175 has 700 hours and a single stage snowblower on it. I know that one, ive used it again and again! That’s the Kohler 17 series 1 twin. New fuel line and filter, changed oil. Wouldn’t start today, i had to pour a small bit of gas down the carb, and it fired right up. Once I got three lane’s cleared, no off colored smoke. It sounded like a dead cylinder. Then, shut the PTO off and let it continue to run and it would come back to both cylinders?? Both the 417 and the C175 engine is completely dry from snow. Now ive changed plugs in both of em to champions (what they were stock). I didn’t change plug wires or coil. What about water in the carb? Water in the carb would be my first guess?

 

Now, the 417A Kohler twin series 2 1200hrs, brand new to this machine! Two stage snowblower on it. Changed oil,  new fuel line on and fuel filer on, new champion spark plugs. Starts quick!! It was running fine and then small bit of black smoke and running rough. Same thing though, once you turned off the PTO and left it sit running it would start running right again. I have no clue on this machine. 

[pfrederi 18,223]

Back when I actually had to use a snowblower on a WH I had a problem with her running badly.  Turned out all that snow blowing around some moisture had gotten into the points...guess the little rubber gasket had dried out

[lynnmor 7,514]

In real cold temperatures ice can form in the carburetor, when throttle is reduced the ice can melt.  Try blocking the cold air and possibly pull air from the muffler.  Tecumseh engines on generators have air intakes that can be turned towards the muffler in cold weather.  If you altered the exhaust it might be part of the problem or maybe the fuel contains water.

[AHS 1,482]

3 hours ago, pfrederi said:

Back when I actually had to use a snowblower on a WH I had a problem with her running badly.  Turned out all that snow blowing around some moisture had gotten into the points...guess the little rubber gasket had dried out

I was thinking that on the 417…it ran beautiful before. I knew it was getting enough fuel, cause that was the black smoke. Then points thing crossed my mind. I would bet 95% that it would start today.

 

[AHS 1,482]

3 hours ago, lynnmor said:

In real cold temperatures ice can form in the carburetor, when throttle is reduced the ice can melt.  Try blocking the cold air and possibly pull air from the muffler.  Tecumseh engines on generators have air intakes that can be turned towards the muffler in cold weather.  If you altered the exhaust it might be part of the problem or maybe the fuel contains water.

The air is coming from the muffler.

[AHS 1,482]

What plugs are you guys running on KT17’s? I had a hard time finding champions. 

[pfrederi 18,223]

I use ABC plugs....Anything But Champion    Have Autolite #25 in a couple of them.  You might want to pick up the tins and round air cleaner on later Series II and Magnums You move the air intake to a place by the exhaust manifold in winter.

[AHS 1,482]

1 hour ago, pfrederi said:

I use ABC plugs....Anything But Champion    Have Autolite #25 in a couple of them.  You might want to pick up the tins and round air cleaner on later Series II and Magnums You move the air intake to a place by the exhaust manifold in winter.

I have both swung over by the exhaust. Let me change the plugs and clean the points. I think i have some points gaskets somewhere.

[Brockport Bill 1,789]

1983 c175 Series 1 winter breather position