My Uxv 500 has the same starting fine, then off for 30 minutes and will not start. Spark, fuel and air check out, pull and clean plug, got spark, fuel pump pushing fuel, but still not even a sputter. Removed and cleaned carb, reassembled and fired up ran great. Stopped briefly, then same problem ?!?! Any suggestions?
SOLUTION: As noted elsewhere in forums, the problem was intake valve out of adjustment. Now runs and starts without issue.