I just recieved my new round top repair kits from ZTherapy. Thanks Pam, Bruce & Steve. After trying the standard jet adusting methods a few times, the piston would drop until that 1/32" from the bottom. I tried adjusting it dozens of times to free it up. The last turn of the wrench would always cause it to stick.
I doubt that this is new but I haven't seen it in any forums. Everyone let me know why I shouldn't do this if it works so well.
Method:
Needle-set to height
Install the spring and round top with damper rod removed
Loosen the jet adjuster nut
Install the jet
Using the choke lever, not the linkage, carefully check the alignment of the choke linkage to the jet. Adjust if needed. Then install linkage.
While lifting and dropping the piston repeatedly, slowly tighten the jet nut until the piston slows or stops. Loosen the nut a little and using a non invasive item such as a wooden spoon handle put it down the oil reservoir hole and rock the piston back and forth all directions. Tighten the nut a little and check piston drop. I got mine centered on the first try.
Mark in Portland