Boat prop issue

[Nateansay]

I have a 1990 Dynatrak 194 STE with a murcury black max 150 2 stroke on the back. I currently have a 19pitch on it and at full throttle without trimming up it runs at around 5200 rpm and as soon as I trim up a little it goes to 6k and I can only get 47 as top speed out of it and I’m looking to get faster top speed as of rn it jumps out the hole quick but not really well top speed what do I need to do prop wise

 

[Chris1956]

Show us a picture of the transom, especially where the antiventilation plate falls in relation to the bottom of the hull. What is the height of the transom? I would expect a 20" transom.

 

[Nateansay]

Show us a picture of the transom, especially where the antiventilation plate falls in relation to the bottom of the hull. What is the height of the transom? I would expect a 20" transom.

 

[Bob Sander]

Yeah... it sounds like the prop is coming out of the water (transom too high for the motor).

The anti ventilation deck on the outboard needs to be (at least) even with the lowest part of the hull. If it's above then you will suck air in and cavitate when planing

 

[QBhoy]

You’ll need more than a 19” for sure, if the gearing is as it was when it left the factory. I’m surprised it’s only doing those rpms even.