We have a problem on our 1996 Super Sport Nautique with GT40 EFI V Drive.
At the weekend with 750lbs ballest and 4 people onboard pulling a wakeboarder the engine revs would go up for a split second under hard acceleration, it was fine if we pulled the boarder up at normal speed.
I am going to change the ATF in the velvet drive to see if that make a differnece as im not sure when it was last changed, the fluid in there was just above the lower indent on the dip stick and the normal red color (not milky).
Would old oil make the drive slip? Do i need to fill it to the second indent on the dip stick?