RE: Problem breaking-in a ASP 120
Raul,
One thing I have seen in the past is a blockage in the carby. The blockage can sometimes float around inside the carby and create spasmodic interruption.
A quick fix is to place some fuel tube on a medical syringe. Fill the syringe with fuel connect the tube to the carby nipple and flush the syringe in and out. You may suck out any blockage.
OR
You can remove the carby from the motor. Remove the needles and the rotor.
Find a jar that will hold the carby,put the carby in the jar with enough fuel to cover all the bits.
Put the lid on and swirl and shake the bottle. You may see the blockage come floating out. Reassemble and reset the needles as above posts and also make sure the throttle stop screw is set as above posts.
Cheers
Chris De Jon