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Help with prop selection

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recoyle3

New member
"hi all I just put together a

"hi all I just put together a project to say the least. I have a 1979 skeeter dual console 16ft. bass boat. the only prop i have is a stainless steel 13 1/8 x 16 prop the boat ran well extreemly fast jumped right up on plane sounded great but my new faria tach was peged over 6000 Good thing the engine didnt come apart on me. I am a marine tech by trade and i know the only good way to determine the correct prop is trial and trial untill optimum rpm range is achieved but I dont have all that money to keep on trying new props. Im only in the field two years and some tips from an experienced tech would save me alot of trouble money and time. Or any links worth while would help also im in florida and i dont know the sea level or the weight of the boat or model so mercury prop wizzard wont help me maby you can, thanks in advance."
 
"This is only what I have read

"This is only what I have read in the topics on this site,,,,for every greater/lesser degree of pitch you lose/gain 200 rpm,,,,
So if your engine as a limit of 5400rpm and you have ran it above 6000rpm,,,you would need to lose at least 600rpm ,,, so a prop with a pitch of 19 would be a starting point, more knowledgable posters will give you better info,,,,,,but I hope the above gives you an idea of what is needed,,,,,"
 
"James has it about right.

"James has it about right.

The best that we can do is give an educated guess as to what would be best. It is almost impossible to nail the perfect prop on a first stab.

It could be done if you can calculate (down to the last pound) exactly how much your rig weighs when it hits the water.

So that would be boat, motor, fuel, batteries, gear, people, water (if you keep a livewell full, or partially full etc), and any other "stuff" you have on board.

Since that may change drastically from one trip to the next (compare an outing with 4 guys - the weight will drop by maybe 600 pounds (or more) if you go out by yourself).

We could start with a "best guess" of what your motor was capable of turning on your current prop - 6200 rpms maybe - if so 4 more inches of pitch "might" get you 5400 (unless it was over revving in the first place with 4 on board - by yourself you could easily add another 400-600 rpms to what it was turning) - see the dilema...

I do have to say however, that just thinking about your rig, 16 foot bass rig, with a 115 and 16 pitch prop (15-19 would be "normal" depending on loading) - that sounds about right - are you sure the tach is reading properly."
 
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