Hey guys, new to the forum but not new to skiing. My university's ski club has a 2005 Moomba Outback which has recently started having some problems. Everything is fine until 3500 RPM, at which point the boat starts jerking. It basically feels like someone's constantly punching the throttle and pulling back, punching the throttle and pulling back, etc.

We think it's the engine misfiring at the second stage due to the consistency in the RPMs where it occurs. We first tried replacing the fuel filter, but that did not fix the problem. Does anyone have any suggestions on where we should go next?