Hello Shawn,
I have had a lot of Fox 35s, 45s, 50s and sorts of other Super Tigre, OS Max, Enyas, Mcoys …….. and the list goes on and on. The thing I had learned was what has been mentioned over and over was a proper break in is a big factor in first flip starts. The other factor is know you engine, not all will start on the first flip with the same prime, you have to experiment. But I have found another way to start any engine was to choke off the venturi and hold the prop, not flip the prop and turn it over a few times, then flip it a couple times to see if there is enough fuel fro a good compression “POP” without the glow plug energized, just to get the engine lubed if this is going to be the first start of the day. Then I would energize the plug, hold the prop, not flip the prop and choke the venturi as I turned over the engine, once I felt the ignition “POP” then I would take my finger off the venturi, signal for a start and then flip the prop and usually the engine would start on the first flip. The main thing is fly a lot, get used to the engine and you will figure out to first flip any engine.
Mike