I'm assuming this has to do with my drive. After 1500rpm the starboard motor slips and spins out of control to 3000. Feels as if the prop feel off. 33OL, 7.4mpi, bravo 1, 27p mirage plus. Is it my drive or maybe the prop pitch? Boat originally came with 454 mag mpi 23p mirage plus.

I'm guessing its your drive hub, its bolt to the flywheel and has spline that the outdrive slides into. Has a rubber cushion to it that after time will spin on itself.

To replace it you mush remove outdrive, and motor.

If it was me I would replace both as usally the 2nd one isnt far behind.

Do you smelling any burning rubber when this is happen (may not if hatch is closed)

Mike

That's way to much prop for those 454's, I ran 25 M+ on my 33 OL with 502 mags and could only turn them 4900, did it start happening after you changed props

Check PROP Hub.
To replace this you will need to remove PROP.

Definitely not the coupler Mike. They're brand new and this is only the second time out and haven't ram for more that 5 minutes each time. Those couplers with idle time on the hose only have about 2 hours on them.

I wouldn't doubt they're too much being that the boat came with 23p on 454 mags. These props came with the engines on trs drives off a 78 cigarette 28ss. I figured I'd use the same props that they came with but I can swap back to the props the boat originally came with no prob. But would that cause this to happen? I would expect it to run just not reach its peak performance???

+1 on the hub! The mechanic here at my marina just said I probably spun the hub. I can change them in the water and be back out in an hour. If that's it great!!! I was more afraid the drive was spun on the inside, but if that were the case I would probably hear the gears clinking and clonking inside right?

Mechanic here also mentioned ventilation. Possibly one drive higher than the other. Adjust trim and see what happens? That's if the hubs are good

don't you have trim indicators

Are the props counter rotating? if not just swap sides and see if slip follows prop?
If it is Prop hub get them both replaced.

Yes I do with brand new livorsi actuators and Mach zero cables. But.... the drives are different, appear to be different years: one has low water pickup one does not. Is there any difference in size and shape? Or can this have an effect on my ride?

Those are the drives that came with the boat however. And I put them back on the same sides they were on I didn't remove the back plate for the steering rams and tie bar. I did put a new tie bar and left it about 1/8" wider than the 36" drive centers.

Yes counter rotation they both spin outwards.