Prop recommendations please: 20' Seafari w/ 150 Johnson OB...

[Bushwacker]

The Michigan Vortex is a good aluminum 4B prop and the 15x17 size should be about right for a 150 motor on your boat, depending on how much load you carry. Their 2-piece hub system is also quite robust and similar to the BRP props. If you get an accurate digital tach and find out that you’re a couple hundred rpm over or under the 5500 target, it can be repitched lower to get more rpm or cupped to reduce rpm.

I selected a 15x20 version of the Vortex that I later had repitched to 15x18, because I made the same mistake that most folks do, ie. not testing with max weight! Once I started testing with a full live well (~15 gallons) and a couple of 60-70 qt coolers full of sea water to simulate the load I typically carried with several divers or on a long cruise, I realized that I was over propped! I ended up with a SS 4B PowerTech ELE4 which used the Michigan hub system and worked very well. I had an awesome hole shot and allowed me to easily run at any speed between a min planing speed of 12-13 mph and a max cruise of 30-35 mph at about 4500. Optimum cruise was about 3750 and 27-28 mph and about 3.7-3.8 mpg on the 150 E-TEC. I ran it for several years until I tested the Cyclone and discovered I could run it higher with a jack plate and pick up 2-3 mph at WOT and get a solid 4.0 mpg at cruise!

[jtharmo]

Originally Posted by Bushwacker

I selected a 15x20 version of the Vortex that I later had repitched to 15x18....

John, this Vortex 4B prop is now in my garage collecting dust. The Cyclone is the primary with the superior performance Denny found. The Powertech is in the cuddy as backup. I don’t know that I would ever have a need to use this. If you want to try it, it’s yours. I would rather see it used. I checked shipping rates to Long Island. It’s maybe $30 if you’re a little patient.

[JUST JOHN]

Originally Posted by SSPBill

John, this Vortex 4B prop is now in my garage collecting dust. The Cyclone is the primary with the superior performance Denny found. The Powertech is in the cuddy as backup. I don’t know that I would ever have a need to use this. If you want to try it, it’s yours. I would rather see it used. I checked shipping rates to Long Island. It’s maybe $30 if you’re a little patient.

Wow Bill, thank you!! PM'd.

[Bushwacker]

You’ll need to get a splined adapter from any Michigan dealer to fit that Vortex prop. Bill needs his for the PowerTec prop. They used to be about $20.