Well, the Asian carbs with these 440 kits are driving me crazy. On the 660 kits, I got all the carbs to work well, and only had to play with the fuel lever height on one of them, and I had no problem knowing where to adjust it.
Saw #4 fired on the 7th pull (not bad for a dry, never used carb), started 2 pulls later, idled fine and tacked up w/o hesitation. I really though I was good to go. I bring the saw up to my property, go into the woods and find a nice Ash tree that the wind took down, and try to start the saw. I checked that the choke was on, and 2 dozen pulls later, still not a kick.
So I open the fuel cap and pour a little mix into the air filter cover, prime it, and it starts and runs. Cuts through the Ash like it is butter, I'm pleased. So the next day I want one of my relatives (who is a tree guy) to try it out. Saw still won't start. We prime it 3 times. Each time it fires and runs a second or two, then dies.
I bring it home, and today I try to start it again … no go. So I put a used HD-16b on it. Kicks on the 5th pull, fires two pulls later, and runs great after a bit of tuning. I put it in a big piece of Black Oak and it did well. I would describe it as very fast with moderate torque, and I was happy with how it cut.
Vibs with the OEM piston are a lot less that with the AM BB piston, but they are a lot smoother with a 440 piston.
So, all 4 of the Asian 440 carbs needed the diameter of the choke plate reduced, or it would stick. Saw #1 did not need any other work and runs well with the 044 P+C. I rebuilt the carbs on #2 and #3, and #3 ran fine after that, but #2 still did not run right and now runs with a ZAMA CM3. I may try rebuilding this carb (#4) after I get more kits, but I still have a few OEM carbs (both ZAMA + Walbro).
If you put an OEM carb on either a Asian 440 or 460 tank handle, put a small piece of 660 fuel line on the end of the carb control lever and your choke will work just fine. It is a lot easier to do this before you install the carb.
Also, lube the crap out of the control levers before you move them, then work them in a bit before you use them. Fluid Film seem to work well for this. Spray every contact point on the control lever, and the metal kill switch stuff.
If you don't do these things, you are going to have issues with the AM stuff.