The FITCH system is not easy or fun to work on, when there is an issue.
First... check all the fuses. (your ski has 2 breakers, and one is just for the fuel pump)
Second... check the plugs around the engine. (They are known to corrode, and loose contact)
Third... check the individual parts. (make sure the pump is OK, and the ECU is putting out power. Check the coils, check the crank pick-up)
If that all checks... the FITCH computer may have gotten damaged.