Every engine runs differently (& needs a different size jet to run at it's best).
Your best bet is to buy a complete set of jets & experiment with it... but be very careful not to jet it too small because it will feel like it's kicking a$$, but it will also be burning up the piston dome!
I like to slowly jet one size smaller & stop right when the 'sputtery' feeling stops... this way you know it's still closer the heavy side.
So I got a new HP carb. Put it on and it starts up fine and idles and warms up and even made it a bit quieter, but when I got to give it any gas it just wants to bog and die. Starts up just the same afterwards. So I took jet out of my speed carb and my nt carb that both turned out to be the same ones but were slightly bigger jet than the HP carb. Think they were bout a 69-70 and the HP carb is a 71. Regardless of which jet I put on , they all perform the same. Idles just perfectly. Rev up engine great. Maybe the NT and speed carb jets sounded a bit better but achieved nothing different. So with all the blah blah I just told you, which way would you veer towards? Bigger jetting or smaller? I'm in Portland Oregon and I,think,I'm 0-100 ft above sea level no matter where I ride. Unless I,hit the hilly parts of town. Hope someone can give me some insight. I really want to use the HP carb but havnt yet and I bought probably 3-4 months ago.
PJ I don't know the HP carb but you're overlooking something, is the bowl full of fuel ? Some carbs have vacuum lines that need vacuum to operate them. If you have a set of jet bits try drilling out one of the jets a size or two and see if that helps.