Update: Gas spaying from muffler & idle air adjustment

[oli]

I originally posted about gas spraying from the muffler on a 15 hp. Kohler command engine on start up, and later about how to adjust the idle air needle on a Walbro LMK carb. This engine has a fuel pump. The engine would spray gas from the muffler and blow black smoke on start up but ran fine at high speed. If left on low idle, it would begin to blow black smoke and eventually stall. I cleaned and rebuilt the carb with a new OEM float needle, and polished the the seat. There was some improvement, but I was unable to adjust the the low speed idle air needle with any effect. My conclusion was that fuel was leaking past the needle and seat and caused the engine to run rich and eventually flood at low speed. Running at wide open throttle seemed to overcome the excess gas going into the carb. Problem was solved when I replaced the carb (OEM). Thanks to all who responded to my original posts. I hope this explanation can help someone with the same problem.

[KE4AVB]

I have been in and out lately so forgive if this is a little late you did know there were replacement needle seats for the CV and SV single cylinder Walbro carburetors didn't you?

[oli]

Yes, I was aware there was a replacement needle seat for the Walbro LMK carb. I watched a few YouTube videos on how to do it and concluded that for me were just too many things that could go wrong in the process. I am not a pro, and decided to just go ahead and replace the carb. Thanks for your response.