TOP SPEED

Boater29

1999 RINKER 272 454 MAG MPI B3 DRIVE WHAT SHOULD I BE GETTING WOT.

Handymans342

You need to read the recent threads on RPM

Aqua_Aura

Well first welcome to the forum. I see Handy has introduced himself 🤣. 

Looks like Max RPM for the engine is 4600-500 just checking online. That is most important to make sure your prop is sized correctly and the engine is running well to achieve that RPM range. The speed I am not sure as I have a different boat. On my 2007 280 with an 8.1 I get about 25 KTS at about 3300 RPM and I don't press it much above that. My boat bottom is not clean though. 

mattie

I'm gonna guess 48-50mph. 

Do we win anything??

LaRea

Yes.  Chicken dinner.

oscar1

What is the need to know your top speed anyway. I always cruiser around 20 to 24 kts myself to enjoy the ride.

YYZRC

IF YOU’RE NOT FIRST, YOU’RE LAST!

Grahamu

Said the tortoise to the hare 

Michael T

You don't need to know your top speed BUT it will be a by-product of what you MUST know - your RPM at WOT to ensure it falls within its specified band - better to be pushing the rev limiter or top of RPM band. Simple, easy and absolutely necessary for the health and longevity of your marine engine. Run it up to WOT to ensure your boat is propped/geared/loaded to fall within that range (max RPM best) then go whatever RPM or MPH you want. RPM is the key NOT MPH!

randy56

I use this prop slip calculator for my outboards. Not sure about duo props.

 https://www.mercuryracing.com/propellers-overview/prop-slip-calculator.html