Had problems with idle speed. Had carbs cleaned and adjusted and now idles great and in neutral sounds great all the way to high speed but put it in gear and it bogs down and will only get to around 25mph. It has all new powerpacks, wiring harness, rectifier, it also after running for about 5 min. will suck the primer bulb closed and cause engine to shut off. I have replaced gas lines, bulb, and filter. When the bulb sucks shut I can shift to neutral and it will immediately inflate. Any ideas?