I have a 196 clone engine that I've installed a flat top piston and billet rod in. I added a 22mm mikuni from go power sports. The sent a 140 main jet and a 17.5 pilot jet that are supposed to be close to what I need for this engine. I can't even get the enine to idle without playing with the choke. I've gone all the way up to a 37.5 pilot jet. With that jet I can only open the idle air screw about 1/4 turn. I've checked for air leaks by spraying brake cleaner around the intake gaskets and all seems good. I rechecked valve lash and cam timing and that is fine. I need some more ideas on what I'm missing.