My 1999 Mobius has been doing a similar thing, but feels
Like it is choking out while pulling a skier. High speeds and high RPMs will bring it on after about 4 hrs of use. It never dies tho... Just kind of surges. Surfing and wakeboarding don't seem to affect it. It has no problems starting. Put in a new carburator, thinking that was the problem with no change. New high power fuel pump too. Sea foam, Heet, and ethanol free fuel. Does anyone have any ideas?