i built a custom chopper using an 01 sportster 1200 as a doner bike. after completing it i have a problem under hard acceleration in 1-3rd gear. the bike starts jumping / bouncing / shaking violently but quits if i let off the throttle. i am running a completely stock motor with stock ignition, stock carb. i have eliminated the VOES by running a ground wire to the ignition and have also eliminated the rollover switch with a ground to the ignition. any ideas on what may be causing this problem? i followed the stock wiring diagram very closely during the build and have double and triple checked all grounds and connections. all connections have been soldered and shrinkwrapped. i have also been having a problem with the battery going dead after about 2 weeks. i suspect the regulator may be bad, i replaced the stator and that got it charging again any help or ideas would be much appreciated. i should have added that i have checked and double checked the belt tension, primary chain adjustment, wheel bearings are new, tires are new, belt is new, running a 250 rear, and a springer front. basically the whole bike, frame, etc. is new with the exception of the engine/tranny .