Having some issues with a factory Nikki carb that has been modified by EC. From what I see, it has been bored, ported and the main jets removed while an adjustable needle has been fitted to the (metal) bowl. The thing idles good (fairly rich, but not adjustable), always runs fantastic out of the corner under WOT......most of the time but not always around the middle of the strait, it will bang out and start running really bad around 5K (turning a little over 6K)....I know it could be rich or lean, but it won't clear up either way I make a high speed screw adjustment. I pull the plugs and one side looks good, but the other is charcoal. I change plugs just to run a heat or race and it'll run good for 5 laps and then start missing again due to a fouled plug. Pull plugs and the same thing, but on opposite cylinders. I've cleaned the carb and find no obstructions or bad gaskets. I know these carbs and I know what is common gaskets or issues, but I have made sure those issues aren't present.
So, I figure I should be done with this carb and just upgrade....anyone use the ECH203-1
carb from EC? I see that it has an adjustable idle circuit and I like that part. I also like the ability to change jets, but hate the amount of trouble it would take to make a jet change....especially if it were at the track.
A bit of background....I have been studying and working with carbs for well over 15 years and I know how they work, but I work on stock carbs, not modded or performance units such as this.
A bit about the motor. 93 octane GASOLINE, precision cam, ARC rods, ARC FW, stock model 40 heads, stock air filter system with K&N filter, otherwise completely stock.