70 hp ftlec won’t rev and surging

Hi guys, some help would be great. I have a 70hp evinrude 4 stroke. (E70FTLEC) on a 24 foot pontoon. It won’t rev past 3600-3700 rpm and at full throttle acts like it’s bogging. It also slightly surges at about 3/4 throttle. Starts and idles perfectly. Check engine light is not on. I’ve replaced the fuel separator at the tank and the fuel lines from the tank to the motor. Replaced the first inline fuel filter. Replaced the neutral safety switch and replaced the impeller. It also dies when I go down to idle or neutral quickly but will immediately start back up when I turn the key. Any help would be appreciated. Thanks!

Cleaned the vapor separator tank?----Check float valve in separator tank ?

racerone said:

Cleaned the vapor separator tank?----Check float valve in separator tank ?

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I haven’t yet but hopefully I’ll find time today or tomorrow. I also plan on doing a fuel pressure test.

Check for spark on each cylinder. Mine had a bad coil.

On the motor itself there is a shift switch for neutral.-----If ECU get a signal that motor is in neutral still , it will not go to full power.