I would bend out the metering arm under the diaphragm just a little, sounds like you're leaning out. Moving the meter arm up will richen at all screw settings, lowering arm leans at all screw settings. Getting it set right is a bit fiddly about 0.030" might separate too rich from too lean. If you apply choke (like putting your finger over the intake) does engine run OK, or does it immediately die? If it runs Ok, you need to richen up, if it dies, lean out. If you have new internals in carb, look for other air leaks, a loose muffler can make tuning impossible. Bad bearing seals can be a problem.I would also inspect fuel lines for cracks and kinks. Just had a fuel line coupler plug the other day, and saw another flyer with a kinked hose after some field repairs.