Normally when one has to have the choke pulled, either the carburetor has stopped up passages, or the fuel delivery system is not keeping the carburetor full of fuel. I would suggest checking the fuel delivery system. If that checks out OK, then a carburetor rebuild is probably in your future.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop