2000 Johnson 130 hp poor idle, bogging to now no start

2000 Johnson 130 hp V4 model j130vxsss with VRO and 360 approx hrs. Great running motor till now. Last operation ran fuel tank to near empty and first use after refill noticed an intermittent poor idle and occasional misfire/bogging. Thinking fuel/fuel delivery problem changed fuel filter and and while running on muffs noticed plug four arching from boot to plug. Changed wire and plug and thought all is well. Next use poor idle, bogging, loss of power worsened and motor now getting difficult to start. Hooked up an external fuel tank to isolate fuel system from fuel/water sep back to fuel in tank. motor started fine but right after leaving dock same bogging,sputtering, loss of power. Noticed tach jumping around and not indicating what was going on at the motor. Barely made it back to ramp before the motor shut off. Motor would not restrart at this point. Pulled boat and noticed fuel dripping from prop exhaust and plugs black and wet. Checked for spark on all 4 cyl and showed strong blue spark. Any suggestions what steps to take next? Thanks for the help.