Hey Dave Wetten
Fuel delivery / starvation it sounds like. Also what year and model number? So I can look up parts?
1) Rebuild fuel pump
2)Clean rebuild Carbs
3) Run Champion plugs
4) Check inline filters/water seperators and if suspect buy new ones
Also I have a rubber "boot" section of my top cylinder spark plug one time crack and let some of the spark ground out. Which made the top carb flood. But the sound the engine made when it did this was way diffrent then just bogging down from fuel starvation/delivery. You can tell by the sound when the engine acts up if its spark or fuel starvation.
I would while your doing all this pick up some cheap in line psark testers and check the spark while it give you these syptoms. Like this one.
http://www.harborfreight.com/90-inline-ignition-spark-checker-4445.html
BTW, Evinrudes have their own section above "Other outboard brands" section.
Let me know what you find or think.
Thanks,
DamianJP