I also have a new OS 46 AX that I put in my well-worn trainer to complete the break-in process. Compared to the Thunder Tiger .46 Pro I've flown for the past 4 years in the trainer, the 46 AX pretty much starts instantly. I still have issues with the TT starting/running backwards. On the AX, I simply hit it briefly with the starter and it's running.

Also be advised the AX has a rear-mounted remote needle. There is a bit of a lag from the time you adjust the needle until the engine recognizes the change so be patient. I use the stock A-3 plug and didn't change the low speed needle and also had pretty consistent deadsticks. It didn't help that my low end servo limit isn't quite set up right.

I began closing the low speed needle about an eighth turn at a time and have the idle and transition better but there still seems to be a pronounced midrange richness I've not yet been able to tune out.

I just sold my beloved trainer so will have to complete the tuning on the intended Somethin' Extra ship once I complete the build.