First impression of 300 V8

[CUDA]

20 some years ago I had a 80hp on a 24 toon

I stripped it down,

flipped it over on it's trailer and took it to a welder, He welded corners on both lower part of the tube to create a surface area to change it to a planing hull, installed new seats and deck was going to buy a bigger motor and my wife said sell it, mistake after all that work.

Wife got scared one day on open water, said she felt safer in a Real boat

it's easy to scare my wife

There is a time and a place for everything.

[mjw930]

Not sure about the 300, but I know on the 450's, the ECM will pull percentage of power at WOT so to not hit the limiter. Basically, reduces HP rather than slamming the typical "rev limiter" we're used to on the 2 strokes. Only way to know for sure is either up the pitch or plug in the computer.

I believe all of the new motors have adaptive speed control. To properly dial in the prop you really need the Mercury CDS G3 app and a laptop to monitor engine demand. It’s not an absolute requirement, they document a way to select a prop without it but it makes it much easier. Here’s a video that describes it.

https://p.widencdn.net/v7mcw2/ASC-Propping

From the 300R service bulletin.

[G-Train]

Raceman, Try the Rev 4 (14 5/8" Dia is what I believe they are). I've got a 19p on my 300xs 1.62 gears. 22' Manutou SHP TRi Toon. 55 MPH, approx. 6000 rpm, thought it might be faster, but haven'y messed with it any more. Want to get a 21p Rev 4 for next year.
All the Best
G

[V-bottom]

Maybe try the Spitfire prop.
I don't have a 300, but with my 115 opti on my pontoon used a 17P trophy prop and it ran 35mph and worked awesome. I upgraded to 115 4 stroke CT and the same Trophy prop off my opti was useless. Half the speed @ 16mph at wot. We added extra cup to the trophy and no change. Tried 6 different styles of props. The Spitfire (17P) was the only prop that finally hooked up and got me back to 34mph.

[RSWORDS]

Not sure about the 300, but I know on the 450's, the ECM will pull percentage of power at WOT so to not hit the limiter. Basically, reduces HP rather than slamming the typical "rev limiter" we're used to on the 2 strokes. Only way to know for sure is either up the pitch or plug in the computer.

All the vew V6 V8 motors are like that and its critical to observe demand, demand linear while testing for max performance.