Got a weird one that has me stumped. Motor starts and runs great just when going forward cant get past 1500rpm with WOT just sounds like its begging out. Flip it to reverse and have lots to go backwards will rev way past 1500rpm if move the throttle on carbs. Tilt the motor right up to point that prop almost breaks top of water going forward motor revs right up and shoots up 15 foot rooster tails. I have checked spark which has lots, compression on all three is all around 110psi mark, cleaned the carbs twice, cleaned the fuel lines. I'm completely stumped as to what could be causing this any idea right now is worth looking into.