Vector/Merc 1750 Setup

Dear Randy,
I have a 77 Vector with a 78 Merc 1750.  It has a Bob's 5" hydro jack, solid mounts, dual ride guide and a foot throttle.  What prop or props would you recommend for this set up?  I want to add a low water pickup cone yet this spring but am not sure if it will help or hurt top end. What are your thoughts?  What speeds should I be seeing?
Thanks.  Craig R. Nelson, Waupaca, WI.


 In the past, that engine with a small blade 26 in. Chopper would run in the high 70s (77 – 78) without a jack plate.  The prop shaft was about 2˝ in. below the bottom.  I found sometimes the jack plate would hurt performance more than help it.  Why?  When the Vector was designed a V-6 didn’t exist yet so it has a problem carrying tail weight.  Moving the motor back increased this.  Put another way, I’ve found 2˝ in. below without a jack was faster than 1˝ in. below with a jack.

 The early 1750 Black Max had a very blunt gearcase.  If it’s the original you would benefit from a cone.  If the gearcase is newer you would see no gain.

Some other props:  big blade choppers with blade area and cup removed.  Hoss Triton I props or there about.  Any good round ear, but beware some manufacturers’ small-pitch props run much slower than the same prop of slightly larger pitch.  That’s why I like the small ear Choppers if you can find one.  They haul every time.


Please submit whatever questions you have to  All questions and answers selected will be displayed on this page as they come in.  Note: though all boaters are welcome, priority may be given to I.H.R. members.  Randy can not be held responsible for any advice given.  Though his information and expertise is second to none, he has no control over what you do with your boat.  It is up to you to boat safely and act responsibly, and his advice is only to be used as a guidance for your high performance boat/motor of which you are the one responsible for the risks involved.

Mark C.

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