do you still use the original gear selector? maybe im forgetting and just need to read back. the little toothed bit that the gear shift lever locks into, if you space out the grooves in there so it's got more room to pull and/or release that's the other big piece to getting away from the thing where it drops outta second.
I always lose oil on the pedal shaft seal, I think the chain hits it sometimes. funny I also had problems with the rear sprocket bolts.
fast sachs is rad. im very excited about this