I have a Kohler K341 16 hp engine I reviled last winter, it was missing the cylinder head carb fuel pump etc but inside it looked really good. Got the parts and got it together started right up and ran so nice, its on my engine run stand and been sitting there since I got it running in March would start it every now and then during the summer and the last couple of times it was hard to start but when it did go it ran fin. Last Friday went to start it and nothing cranked and cranked finally it popped and caried on and ran very poor needed choke then that was to much then it would pop and pop and die, check to see if the fuel pump was working it was had gas in the tank so I got the spark checker connected it had great spark jumped a 1/4" gap so I thought maybe the spark plug (put a new one in last March) got a old good Champion H10C put it in and it started and ran just about perfect, tried it again Sat and it started right off and again this morning started up and runs as nice as can be. Took the new removed plug over to my spark plug tester and had intermittent spark cleaned it good set the gap tested again nothing then real weak spark the nothing> Its one of those plugs that comes with an overhaul kit this one sure didn't last may have 4 or 5 hrs on it
