Yamaha bogging down under load but idles and runs at speed no problem?????

[Shootinfish]

Originally posted this in an on going thread but figured I would start a new thread so everyone could see it in hopes that the more that see it, the better my odds are of a solution.

I have been dealing with this issue for OVER A YEAR NOW. Nobody I have taken the boat to can seem to fix it. I keep spending and spending and each time I hear "I think we solved your problem" first test run out and it does good at first but eventually goes right back to what it was doing before. I have taken it to 3 different places with no avail so maybe you have an idea of something I could try if this has happened to you or know of the problem.

Motor: 1998 115hp Yamaha precision blend

What the boat is doing:

Cranks up no problem. Idles on trailer and in water no problem. can put it in gear and idle around in marina no problem. when I get out of no wake zone and give it some throttle, as soon as it gets under load it wants to bog down and try to shut off. HOWEVER, if I hit the electric choke when it starts to bog down it throws "more fuel" to it and it will then take off. it seems to do it between 3-7mph. Once I hit the choke and it jumps past the part where it wants to bog down and I give it more throttle, it will run like a new motor from about 8mph to WOT and wil run anywhere between those speeds flawlessly all day long. as soon as I stop the boat and start to take off again I have to give it throttle until it starts to bog, quickly hit the choke while giving it more throttle and then it will take off. if I don't give it choke when it starts to bog it will cut off. again, it will sit in idle all day no problems. it will idle around in gear all day with no problems and run at any speed all day with no problems past 7-8mph. Anything in-between in gear idle speed and about 7mph and I have to continually bump the choke to keep it going (like if I want to troll between 3-7mph, I have to continue to bump the electric choke to keep it from bogging and cutting off) it seems to be just when I put it under load is when I have the problem. even driving it on the trailer is a pain in the ass sometimes cause when I put it under load trying to drive it on the trailer it wants to bog down.

What I have done, and what mechanics have done.

1) Replaced complete fuel line from tank to motor incase there was a pinhole leak somewhere.
2) Rebuilt the carbs/cleaned injectors
3) Changed spark plugs and wires
4) Replaced the pump diaphragm
5) Replaced the priming bulb
6) Checked compression- all cylinders were very good
7) A bunch of other stuff that ill probably only remember if someone mentions it :/

Have always used fuel stabilizer religiously in every fill up.

Do you know of anything I could possibly try to help? Have you seen this problem before? If so what was the fix!?!?!?!?! its been so long since I haven't had to deal with the bogging that I have about just got accustomed to going through the motions as if that's how your supposed to run one now