1991 170HP 1.7 liter outboard carb issue?

I have a 1991 240 Proline with twin yamaha outboards. Both motors have ran good since I bought the boat back in February, however recently I've been having issues. Both motors start up, idle and run amazing. And at first accelerate normally, but when I hit a higher rpm, at the point when the throttle passes it's first stop, they both dog out and spit and sputter and then eventually die. They will however run all day long with no issue at around 1800-2000 rpm. I think it may be an issue with the high speed jets, but what are the chances both high speed jets messed up on both motors at the same exact time? I know they have good spark and compression, just this Sunday they ran fine all morning, ( we made it 20 miles offshore) but then after drifting all day they petered out and would do more than 2000 rpm. NEedless to say it was a long trip back in at 6 knots! All the local shops/ marinas are swamped and I would like to get this bad boy back on the water to enjoy the rest or stripper season and tuna before the weather turns. Please help