hey...I'm new here...I bought a 1976 Chappy (had one when I was a kid) and I have re built it...the bike starts, runs, idles fine EXCEPT for when I try to drive it...the gears work fine, but the bike does not take off normal. I have to open the throttle wfo to get going, and it takes a while until I reach 15 mph (then the high gear kicks in) then it takes a while before I hit 20 mph...after I hit 20 mph, it does a little better but can't get it over 33 mph...When I have the bike in low gear, it runs much better....any help trouble shooting would be greatly appreciated...thanks