I am having a bear of a time getting my jets centered. With the locking nut very loose I can get the piston to fall freely and land with a soft thud. As I slowly tighten the nut I keep dropping the piston after every very slight tightening and I get the thud until the nut begins to get tight at which time the piston no longer falls freely. If I use the lifting pin the piston lifts but will not fall without a slight push. The carbs are on the car and I would prefer to do the adjusting there but if all else fails I guess I'll have take them off and try it that way. I have watched John Swift's video and the adjustment looks so easy when he does it. Is there a trick to getting them locked in the proper position???