I have a nasty hicup at idle speed. I checked sparke and a lot of other things as listed below. Spark was good but the story doesn' end there.
I swapped the ignition coil to see if that was the problem, nope still the nasty left cylinder. So I tried th obvious one of swapping the plugs (I don't have new ones just the older ones I had in my garage will get new ones tomorrow). Swapping the plugs seemed to help a little but not much. Also the plug out of the left cylinder was very black, but both the pilot screws are turned out 3 turns and the right looks perfect.
I checked the cab balance and all was well, I just rebuilt the carbs and adjusted the float height. so I guess I am down to checking the resistance and what not of all the ignition system to track this down. The only other thing I can think of is maybe the valve shim clearance isn't right on one of the valve in the left cylinder.
I also checked the grounds and everything was good. Checked the connectors to the coils and the igniter box. all was well.
What is happening now after all that is this. I start it from cold w/ the choke on it only idles around 2000. Once warmed up I turn the choke off and it drops to roughly 1200. While idling it has a blip/ hicup to it. If I remove the left cylinder plug it smooths out, but the RPMs only drip a little if I remove the right side it pretty well dies.
I know this is long, but I'm just so frustrated. Also, I hve not done a compression check because I haven't bought the tool. I wll tomorrow.
Please help me.
is one runign richer/leaner and yes the valve shims could play a big roll