These carbs are SUPER easy to tune and set up. A rebuild kit is like 15 bucks or so. Wouldn't hurt to pick one up as it contains all you need like the power valve/acc pump/etc.
A cold stumble can be low fuel level too...so it's best to set it up at baseline & tune from there.
For a start (on 1.08 models):
tip of float should be 7/16" down from top edge of carb body. (fuel level)
main jest should be 47/48 at sea level -500 ft above (affects 1/4 throttle & above)
Acc pump rod should be in top hole of throttle arm and outmost hole in pump arm. (affects tip in acceleration)
Choke pull off (amount flap opens up from vacuum when motor starts) should be around 1/8" (affects cold start)
Power valve should be a 7.0 or so....the one in the rebuild kit works fine on my mostly stock motor.
Idle air screws should be 1 1/2 - 2 turns out from lightly seated
Assuming your ignition timing is correct, of course.
Take some pics if you can & we'll walk you thru the set up. It's really not difficult at all.