The only time I've seen a 3W not want to pull fuel is the carb block was leaking air where it bolts to the crankcase since there is no gasket there. Unfortunately, this is a somewhat common problem that is pretty easy to fix before you mount the engine. I forget the Locktite version number but it's more of a gel that does not harden. Cactus and AI use it on the CS versions to seal the carb block to the engine.

I originally had the same problem with my 55i pulling fuel but since I used the "gel" that problem has since gone away. My 80xi-cs has never given me a problem but then as I mentioned I do not have that many flights on it yet. From new it took 16 flips to get the first bark and since the first 10 minute flight it has always been close the choke, open the about 1/8th, flip until it barks, open choke, close throttle to idle and roughly 3 to 5 flips and she's running.

I've known other to do the ZDZ starting routine which is 5/5/1

Ignition off, open throttle to full, close choke, flip it 5 times
Ignition off, open throttle to full, open choke, flip it 5 times
Ignition on, close throttle to idle, open choke, flip it 1 time

Now if it's really cold out then on the last part, leave the choke closed, then after it barks open it and 1 flip later

Pat,

Do you know what model Walbro are people going to on the 55 to 80 size? Just curious