Having it trimmed all the way down could definitely reduce performance. I don't know a lot about Kaw skis, but I've heard the trim motor is easily flooded, since the box it is in was poorly sealed. It is probably a bad motor or controller (motor making no noise at all makes me think..........bad motor). If you can wire the motor directly to the battery, you can find out pretty quick. You can occasionally see motor and controllers for sale on Ebay. I'd try to get it into a neutral position and lock it.