Both our 144's did OK with the Yamaha factory settings 40/410... Once broken in and under race conditions the 410 was to lean and now we're at a 420... and most likely will go 430+. Never did have a bogg issue low end... realize however the bike spends very little time mid/low band. I suspect you may have an issue with the air screw setting, check the book, reset and adjust for throttle response low. Other obvious but assumed OK things are carb air leaks, reed seating, etc., sometimes it's the simple things that'll make us pull out what hair we have left.
Good luck and have fun on your 144 4f killer...