If I run matching nozzles and needles (ie. stock)...
#60...it accelerates strong right up to 30. It will 4-stroke if I go any faster such as downhill.
#58...The acceleration is down some. If I don't richen the needle, I have to feather the throttle a bit to get it to reach it's top end...which is now 34. If I raise the needle up, I can get my acceleration back if I don't floor it. 3/4 throttle is it's happiest position until I'm up to 30, then I can open it up all the way and hit 34.
#56...Crappy all the way around. Poor acceleration and it won't climb past 24mph.
#54...Beyond crappy and almost unridable. It's hard to get into 2nd gear.
If I switch the needle to the newer one but keep the nozzle, nothing really changes accept there is a slight lean spot just before full throttle. I can nail it up to 30 and then cut back the throttle just a bit to hit 34 with the 60 jet. It's a bit too lean all the way around with the 58.