wheel horse C-175, Kohler K341 back firing at high idol

[Josh Opitz 2]

I have redone most electrical components and fuel of this kohler K341. new spark plug, coil, starter, battery, rectifier, Carb, rewired, but i have not done points. it starts up great idols fine. when I turn the throttle up it rises up to a certain RPM then starts to seize and puff black smoke and the throttle on the the carburetor jumps. Someone had told me it is backfiring and said i need to adjust the my air to fuel ratio. started messing with the governing arm and spring and thought it was helping but hasn't fixed it. any suggestions?

[oliver2-44 8,852]

Does your carb have an adjustable high speed jet or is it a Walbro fixed jet?  The black smoke seems to indicate it is running rich as it loads up. 
 

 

[Josh Opitz 2]

I believe it does. its one of the cheaper new ones. id have to take the bowl off and just back it out?

 

[Josh Opitz 2]

just was looking around it looks like the high speed adjustment needle is on the top of the carburetor. 

 

[oliver2-44 8,852]

The Kohler manual for your engine will have a good section on that as well as how to set the governor. If you don’t have a manual check the manual section here and download one. 
 

May I suggest you use the manual and reset the governor to protect from an over speed. Then with it running try adjusting the top high speed needle in and out some per the manual to find the best spot. some.
Is your new carb a factory or aftermarket?  Sadly the aftermarket carb could also be the problem.   I’ve bought 3 and won’t be buying any more. One had no idle adjustment response, one no high speed response and one that worked fair.  There selling aftermarket’s one size fits several engine HP sizes. So from the start the orfice in the carb is too big or little.  Mine were also dirty inside with metal shavings from the factory. 
 

Do you have the original carb. They are very rebuildable. 

[953 nut 51,736]

7 hours ago, oliver2-44 said:

There selling aftermarket’s one size fits several engine HP sizes.

The aftermarket junk is not worth buying.

10 hours ago, Josh Opitz said:

I have redone most electrical components and fuel of this kohler K341. new spark plug, coil, starter, battery, rectifier, Carb, rewired, but i have not done points.

Most of your problem as described is probably fuel related but it wouldn't hurt to replace the points also. The setting of your points is what determines your engine's ignition timing so it can make a big contribution  to the overall performance of your engine.

Ignition timing on Kohler engines.

 

Gapping the ignition points at .020 has always been the standard answer to how points should be set. That probably will get you into the ballpark where the engine will run, but with a bit of additional effort you can improve the engine’s power and performance.

The Kohler engine manual in the Red Square files section covers two methods for setting the ignition timing, Static Timing and using a Timing Light.

 

 

[gwest_ca-(File Mod) 10,500]

A bad condenser can cause misfiring. Have another you can try?

It connects to the (-) side of the coil and the body of it requires a ground provided by the mounting bolt.

 

Single cylinder engine?

 

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11 hours ago, Josh Opitz said:

a certain RPM then starts to seize and puff black smoke

Your description certainly points to being fuel related - (black smoke is always fuel) .... but the "starts to seize" comment is worrisome and could be a really serious problem. Could you describe that in more detail -- when it does this does the engine turn over  and not start, or does it literally 'seize' and cant turn the engine over even by hand?