Are you sure the carb plate is closing and SEATING all the way? Reason I say this is because I had the exact same problem with my DA 50..I called them and they said to loosen the screw on the butterfly and wiggle the plate around until its seated tightly..after I did this my engine primes on 3-5 flips instead of 30..It looked like the plate was closed but it was off by a few degrees.