Malossi Force Master hesitation

I have a 2016 GTS300 Super, kitted with Malossi V4 cyl and head and various other performance and cosmetic mods. It was running weak, even with a larger injector and Malossi Lambda Emulator, so I installed a Force Master. This seemed to fix the mixture, but I now have a hesitation at about 1/3 throttle, cruising at 60-80 kph. I have fiddled back and forth with the low and mid-range settings to no avail. I have swapped out the transmission - variator, pulleys and belt - but that made no difference.

Any suggestions, anyone?