Johnson 25hp hesitates getting to WOT

I have an 86 Johnson 25hp. It idles well but runs rough and misses bad at half throttle. If you keep giving it throttle it comes out of it and runs very well at WOT. It is almost like it is running on one cylinder and all of the sudden the other one kicks in. It does this every time you accelerate. I have rebuilt the carb and the fuel pump and replaced fuel lines and fittings. I recently replaced the power pack also. The way it cuts in an out sunddenly getting to full throttle makes me think it is ignition related. I am tempted to replace coils and plug wires but also think maybe it just needs an adjustment. Anyone have any thoughts.

your decision is it a fuel or fire problem?check the compression and make sure fire jumps 5-7 16th of an inch with a tester...then run the boat and use an inductive timing light to make sure you are firing correctly when the engine fails...what you dont want to do is work on fire when its a fuel problem or vice versa...

make sure you timing is advancing...

I had the carb off and thoroughly cleaned and rebuilt. I have already adjusted the timing advance and throttle opening thinking that may be it. I think I have it set right. I kind of wonder if I need to adjust the idle speed needle a little. I tinkered with that the other day with the motor in a tank in gear and didn't notice any changes unless I closed it completely and killed it. I am going to borrow a timing light from a friend too and check out ignition.

Throttle is opening too soon.