Took out 1996 Glastron with a Volvo Penta 3.0 GS engine. It started up after turning over a few times and ran fine. After about 15 minutes of tubing, stopped and then engine wouldn't start again. It turns over and sounds like it's trying to catch (like coughing or belching), but never does. Checked battery connections/wires and used trickle charger to make sure battery was fully charged. 3/4 tank of gas. Kill switch lanyard attached. All fuses normal. I've tinkered with some issues on lawnmowers and older cars before, but never one of these. Any suggestions?