I'm lacking time to reply to each individual comment, but I want to say a big THANK YOU! to all you who threw out ideas. Just because I'm not replying to you doesn't mean it wasn't a good idea, it just means you are not as important as my beauty rest and I'm tired and grumpy. That's a warning, Cat. Don't mess with me.
I have not had a chance to mess with it yesterday or today. Too many other irons in the fire.
I'm going with the carbon idea. Maybe even the head gasket idea. Its worth a try. It has great compression so I was not going that way, but otherwise we're running out of ideas.
sure it's a Kohler? Sounds more like a Tecumseh Snow King to me. Those all run like you say, surge like mad til they have a load on them then when you get into a heavy drift they smooth out. especially the POS non adjustable carbs on the newer ones.
The carb you put on; yeah I know that you said it is brand new but is it NOS from back in the day or is it a newer reproduction? Bad casting maybe?
It is a new reproduction. They do work great. I only have had one that failed me, and that really wasn't its fault. Whoever had installed the main jet had mashed it down and destroyed it.
You do know about a Snow King, though... funny how anyone who has really been around them remembers that surging.
I think I know you better than this, but throwing it out there anyway, might there be a head gasket leak?
May be a dumb question, but is the voltage regulator working properly? Maybe a bad connection that is intermittent? Is your voltage reading the same during the surging?
Is the governor arm connected tightly?
I did install a take up spring on the governor linkage, since it has the typical slop in it. No improvement.
The voltage regulator is an interesting idea, but I did run the engine off a separate battery than the tractor for kicks and giggles and nothing changed. I have had a bad wire or key switch cause ignition woes in my history.
There could very well be a head gasket leak once the engine gets warm, although both a compression test and (excessive for a Kohler K) a leakdown test did not find it. I will try that.
I can't believe someone would actually suggest taking a shotgun to a Kohler engine that is giving them problems. A twenty pound sledge is much more rewarding, and you can curse and holler at it with every swing. The shotgun will only blow holes through the tin, and if you get lucky, you might be able to blow the carb and air cleaner off of it.
OK, I recant of the shotgun idea. I'll bring home one of my mini excavators and rock breaker and really go to town.
Actually, now I'm to the point of where this engine will not win!