I have tried using two carbs and have ended up with the same results. The only way i can fight this 110ST quad is to adjust the air mix screw a 1/4 turn out and the idle screw 1/2 turn out with the choke on with lots of starting fluid. once started and warm I can adjust the A-mix out to 1 1/2 and the idle 1 1/2. seems to run better with the choke on. I have great spark and about 80 psi on the cylinder. what do I do to make this start easier and run better

 

adjust valves, reclean carb/jets, check for air leaks. i.e. cracked plastic intake/missing O-rings on intake at carb/etc.... please be conservative with starting fluid. the quad can get very used to and addicted to the ETHER BUNNY. no wonder you're losing compression. it's starting to wear the rings. keep an eye on oil consumption and any smoke when running.

 

well come to find out I only have 48psi. looks like I will be replacing rings