Electrical or Fuel Delivery?

[ScottM]

Today I used my boat for the first time in over 2 weeks. It has an '89 225 Johnson which didn't want to run very well. It started no problem, I idled from the mooring out the river without issue (3/4 mile), but as soon as I throttled up to about 4000, the engine would bog a bit. The tach would drop 300-400 rpms and the boat would slow down a bit, then it would throttled up again. Below 4000 the engine ran fine, over 4000 up to WOT @ 5600 I experienced this problem. I'm not so sure it's fuel related because the engine wouldn't cut out. I did notice when I hit the trim tabs to make sure they were in the up position, the engine bogged, which leads me to believe it's an electrical issue. We did have lots of rain this past Saturday, so I'm wondering if the wires got wet? Anyone have any ideas as to what this could be?