Originally Posted by ReconBayou

It runs perfect for about a mile. Then it would cough, spit, sputter, backfire and stop running. I can let it sit for a while and it will run perfect for a distance in proportion to how long it would sit. Now at this point I'm sure you are think "it's a fuel supply fool". NOT!!. I took fuel cap vent apart, Blew through the vent tube, checked fuel to carb bowl by opening the carb bowl drain screw and draining a gallon of gas out at a rate fast enough to supply a big block Chevy. I didn't tear the carb down because any problems such as this would act up immediately and forever. Ah ha!!! It must be electrical! I can turbo charge a jet ski, build a 1000 hp small block Chevy, install a supercharger on a 2015 F150, and a bunch of other stuff but I know nothing about electrical. I put a new coil on it ... no help at all. Changed out the ICU. That changed the symptoms but helped not at all. Now it will go the mile and keep on going provided I keep the rpms up. It will do as before if rpms are in the bottom 3rd of rpm range ... exactly where my wife keeps it. OK, now I'm stumped.