I have just replaced the short block on a Kaw FB460v on a JD 165 and can't seem to get it started. My first attempts to start resulted in rough running for a few seconds then the engine died. I've check for spark (looks good), compression is ~70psi, new battery and starter booster, and air gap to coil set to .305mm. I removed the carb and used spray cleaner to clean out the main body, float bowl, choke and throttle valves. It has new gas, filter, and spark plug. Is there something I'm missing? It sounds to me like a carb problem, but I'm new enough to this arena that I don't know exactly what needs to be adjust/cleaned/rebuilt. Any ideas would be greatly appreciated. Thanks in advance.