2015 ultra 310lx losing power on full throttle.

[Lukeferg]

I have just purchased a 2015 ultra 310lx and i can tow the kids around all day on a tube a quater throttle with no issues but when i get on the ski solo and give it the berries it will get up to about 80kph and then lose power and then wont rev over 4k rpm. Will do this every time you go quick on full throttle but will be fine when just keeping speeds to about 40kph.
Any one had a similar issue??
Ski did have a service and where super charger dampener and belt were replaced just prior to purchase.