Just thought I'd throw this out there 'cause I think it's gonna help me in the future. I discovered something by accident last week that helped my tune-up a lot. The carburetors I've been using (Walbro WT-324 and it's replacement WT-891) have a regular choke butterfly in them. While at the field last week the choke butterfly screw came loose somehow and the butterfly blade fell out and it almost sucked the screw into the engine. I discovered that there's actually enough room to sneak a finger in between the carb and mount and choke it by hand so I finished flying that day choking it with a finger to get it started if it was cold. The neat thing is that removing the choke blade and rod entirely had the side effect of changing the tune-up a little. I had to open up the high speed needle almost 1/4 turn to smooth out and maximize the top end. I flew it the rest of the day with that setting and it ran very smoothly and seemed to transition from low to high speed better than it ever has. The next time out the weather was a little different and for the first time ever I didn't have to touch the needles and she ran smooth for four flights. I was very happy with it. I decided to leave the choke shaft/butterfly out of it so I removed the carb and filled the choke shaft holes with JB Weld to smooth out the air path a little and make it so I can get a more positive choke with my finger. I believe that on this engine with this carb when the choke was in place and open it was causing undue turbulence inside the carburetor and possibly even causing a bit of choking effect at wide open throttle. That would explain why I had to richen it up some after I removed the choke and might explain why it's been too sensative to changing atmospheric conditions. I'm guessing that it was choking it a little and I had it set a bit lean for that atwide open throttle then at slower speeds it was leaning out a bit and causingthe sensitivity and transition problems I had sometimes.I'm convinced enough that when I put together the engine for the Gee Bee I'm gonna eliminate the choke from the beginning and probably go with a primer bulb setup 'cause I won't be able to get a finger anywhere near the carb on that one. We're nearing the end of flying season here so I don't know how much more I'll be able to fly with this setup to expeiment but it definitely seems to be the way to go for me at this point...