Does this prop seem right?

gunner1

Petty Officer 1st Class
Joined
May 13, 2006
Messages
375
I just bought a 22.5' aluminum hull Peterborough and it has a Mercury Tracker Pro Series 115hp outboard on it. The prop on it read 13 1/4 x 17. Does this prop make sense for this boat? I would have thought the thing should be bigger.
 

hwsiii

Commander
Joined
Jan 25, 2009
Messages
2,639
Re: Does this prop seem right?

Gunner, if you will fill this out I will help you as much as I can.

You might try reading this for a better understanding of changing props for better performance, and for the major differences between aluminum props and stainless steel.

http://forums.iboats.com/showthread.php?t=369057

Welcome to the forum, I will try to help you as much as I can but without more information no one can help you, and I will tell you I need more information than anyone else. But if you would like my help fill this form out and I will help you as much as humanly possible, if you would prefer to not go to this much trouble there are other people who will gladly help you. My expectations are that you are willing to expend as much time and energy as I will to find a better prop for your boat.

Just copy this form to your computer and paste it into a word processing program and fill it out, then paste it into your post or just use the numbers for reference in your reply and type in your information.

Iboats Boat and Motor Info

1. Year, make and model of boat

2. Length, width and base weight of boat, look for boat decal on back of boat

2a.What is the maximum recommended HP for your boat

3. Number of people and gallons of gas normally on boat

4. What do you use the boat for

5. Is it a Deep Vee and if so how many degrees of Deadrise

6. Year, manufacturer and model of motor

7. HP and gear ratio of outdrive IMPORTANT
If you don?t know the gear ratio, you need to pull the plugs out of the motor and put a piece of tape across the prop and the lower unit and then cut it between the prop and the housing then do the same thing on the flywheel and turn the motor until the tape lines up with each other on the prop, it is easier if two people do this, so one can watch the prop while the other counts the revolutions of the motor

8. Manufacturer?s recommended Wide Open Throttle (WOT) range

9. Anti-ventilation Plate height above the bottom of the transom of boat if it is an outboard in inches, use a straight edge or a board under the keel and sticking out to the anti ventilation plate for a reference, and take about 4 pictures for us to see.

AntiventilationPlateStraightEdge-1.jpg


10. Is it a bass boat or does it have a pad bottom and is it on a bracket, if so how far does the bracket extend from the stern.

11. Does it have a hydrafoil, dolefin, whale tail or trim tabs and is the motor on a bracket, and if so how far back from the stern is the bracket

12. Manufacturer, model, diameter, pitch, number of blades and whether SS or aluminum props.
IMPORTANT
1.
2.
3.

13. WOT RPM and speed from your current prop and how much gas and how many people were in the boat for the test data and is the speed by GPS. Make sure you trim the prop up until it starts ventilating and then just trim in until it quits ventilating. If you do not have a tach you can buy a Tiny Tach for less than $ 50
RPM ___________ Speed (GPS)___________ No. of people ____________ Gal. Gas ________

14. Are you at sea level or a higher elevation, give us the elevation in feet __________

15. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way by only using the control on the console, checked compression, looked at the plugs and checked spark, is the bottom of the boat clean and barnacle free, and have you checked the Tachometer against a mechanics tach, all of the foregoing could be the reason your prop is not attaining full RPM.

16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop.

17. Does the prop show any damage that you can see

18. What problems are you trying to cure or what are you looking for the boat to do that it is not doing the way you think it should or to your expectations

19. If you are trying to attain a better cruising speed and fuel savings or trying to attain a faster speed I will want you to take your boat and run it with 1 or 2 people and give me the RPM and speed readings starting at 3,000 RPM in 500 RPM increments all the way to WOT.
1. 3000 RPM
2. 3500 RPM
3. 4000 RPM
4. 4500 RPM
5. 5000 RPM
6. 5500 RPM
7. 6000 RPM

REMEMBER, The prop I recommend will be NO better than the information you give me.​

The only thing I ask of you is to come back and give me a report of WOT RPM and speed for my database.


H
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Does this prop seem right?

If you fill out hwsiii form he will get you some real details for a suggested prop.
He can even suggest some expected performance details.
You really didn't give nearly enough info even for a rough guess.
Just from the length of the boat and the size of the motor I would guess the prop could even be too big.Without a description of the boat and its approximate weight
couldn't really guess accurately. Without the year of the motor its difficult to
compare available prop size selection.Do you have any performance details?
 

gunner1

Petty Officer 1st Class
Joined
May 13, 2006
Messages
375
Re: Does this prop seem right?

If you fill out hwsiii form he will get you some real details for a suggested prop.
He can even suggest some expected performance details.
You really didn't give nearly enough info even for a rough guess.
Just from the length of the boat and the size of the motor I would guess the prop could even be too big.Without a description of the boat and its approximate weight
couldn't really guess accurately. Without the year of the motor its difficult to
compare available prop size selection.Do you have any performance details?

Like I said ijust bought it and we're a little socked in with snow right now. I know the motor is a 1995. The only reason I'm questioning the prop size is because the PO told me not to run it at full throttle with a light load of say me and someone else because the rpm's will really be high. Sorry I don't have more info. Hopefully the snow will melt enough off of the cover soon and I can look for the factory sticker.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Does this prop seem right?

Could you give us a description of the boat?Is it a barebones fisherman or a full blown cruiser?
From my limited research imo a 22 1/2 ft al.boat would have would have to be pretty light and fast to overrev with a 17" prop.Did the PO mention an actual rpm?
 

gunner1

Petty Officer 1st Class
Joined
May 13, 2006
Messages
375
Re: Does this prop seem right?

Could you give us a description of the boat?Is it a barebones fisherman or a full blown cruiser?
From my limited research imo a 22 1/2 ft al.boat would have would have to be pretty light and fast to overrev with a 17" prop.Did the PO mention an actual rpm?

Here's a link. If you scroll about half way down there are some pics. The only thing that has changed is that the motor is on now. I believe he mentioned he hit 8000 RPM's once, but that don't seem right to me because the motor wouldn't have survived that, right? Not only that, but he said the tach got water in it and no longer functions. Moisture in a tach can throw off readings, correct? He also said that he hit 42 mph on the gps with it with just him in it.
 

trendsetter240

Lieutenant
Joined
Jun 22, 2009
Messages
1,458
Re: Does this prop seem right?

Here's a link. If you scroll about half way down there are some pics. The only thing that has changed is that the motor is on now. I believe he mentioned he hit 8000 RPM's once, but that don't seem right to me because the motor wouldn't have survived that, right? Not only that, but he said the tach got water in it and no longer functions. Moisture in a tach can throw off readings, correct? He also said that he hit 42 mph on the gps with it with just him in it.

You need 3 or 4 things to determine what prop should be on that boat.

1. Boat in the water.
2. Engine in excellent running condition.
3. Accurate tachometer.
4. GPS to determine prop slip (Ideal but not required)

Right now it would only be a wild guess for anyone with the info you have. Also not all 17p props are designed the same way. One 17p prop might be totally wrong for you while another is perfect.

And the 8kRPM is not likely because the power pack rev limiter should cut out at 6700RPM.

You want a prop that places your engine near the top of the engine manufacturers recommended RPM range at WOT with a typical load. You will get the best prop by getting all the info in HWSIII's form.

Cheers~!
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Does this prop seem right?

Here's a link. If you scroll about half way down there are some pics. The only thing that has changed is that the motor is on now. I believe he mentioned he hit 8000 RPM's once, but that don't seem right to me because the motor wouldn't have survived that, right? Not only that, but he said the tach got water in it and no longer functions. Moisture in a tach can throw off readings, correct? He also said that he hit 42 mph on the gps with it with just him in it.

I think you forgot the link.The only thing at the link is a Starcraft.
I would suspect the tach wet or dry.42 seems very fast for a boat that size with a 115.
But I suppose its possible.
 

gunner1

Petty Officer 1st Class
Joined
May 13, 2006
Messages
375

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Does this prop seem right?

From the looks of it I think your about right with a 17. Varify your tach or
get a tach I think you will be right there.The boat appears to be pretty much bare bones except for the floor.Now 42 seems pretty normal.
 

turkk9

Cadet
Joined
Mar 7, 2010
Messages
11
Re: Does this prop seem right?

this post is for HWSiii
i dont know how to get up with you so i am trying to reply to this post. ok so i have researched you and your advice. i have heard alot of wind blowing from alot of lips aver the winter but by all means i have read all and i mean all your post. i have come to the conclution that u may be the only person on the face of the planet who can help me.
ok here goes my real email is 1013photo.com@gmail.com
let me start by telling you what i have as a problem. ok ever try and pull a log out of water? that is kinda like my hole shot. not to to bad but noticable. next is the boat rpm. now eather my guage is really bad off or i am spinning a prop like mad. next is boat speed. at 3/4 throttle maybe a little better the boat is at 46mph (gps) then when i gun it it jumps from 5g to 5600but boat goes no faster.
now i have spoken to several ppl and they say no way my setup will spin a prop that fast must have a rpm guage off. now i can see 2 or 3 mayyyybe even 400 rpm but 6plus???????? dont sound right. pluss i have a pro street drag bike so i am use to hearing rpms and it sounds above the recomended 4800 i beleave. the motor was a 305 spun bearing and now has a 350 with 305 heads and thats all. no rev limiter. keep in mind i would like to stay with a alumin....prop as i am on a budgett at this point. new to boats.

now for the setup i will try and answer all your questions in order
1) 1990 regal valanti 200 bowrider (open bow)

2) 20 foot 8 foot beam 2400 pounds

2a) max hp is 300

3) 3ppl sometimes 4 (if son has a friend over) not sure on gal of gas but allways stay around 1/2 tank 25 gal

4) ride the water with family (tube and ski behind 2 jetskis)

5) it is a v but dont think it is a deep v

6) 350 block 1969 heads 305 1990 (was all i had) stock 2bbl carb

7) alpha 1 outdrive 1990 stock not sure of gear but if i am right there r only one for those older years 300hp max

8) 4800 wot max maybe 5g but i think it is 4800 u will know better than i

9)n/a

10)n/a

11) has a wale tail but will remove on your recomindation if needed but will leave on eather way. doesnt matter 2 me

12) michigan ballistic 23 pitch 3 blade is all i got came with boat

13)wot rpm as of saturday 5600 5500 me and wife 330punds 2 life vest 3/4 tank gas gps 46 mph

14) lake james nc elev 1200 i think

15) motor new

16) not sure how long it has been on boat i bought boat at end of season last year only used about 8 times then winter hit

17) prop looks great and if u suggest a new one i will sell this one cheep

18) i think the boat is a little sluggish @ hole shot and it has to many rpm (if tack i right ) also top speed is it right at 46mph? boat planes at just over 3/4 ish throttle at 4800 ish rpm then when u give it wot rpm rais but speed doesnt

19) shew kinda hard this one but it cruises at 38 to 3900 rpm at 20 to 24mph any lower rpm and the boat comes off plane maybe i can get 3600 befor breaks off plane. 44 4500 rpm is about 40 then wot 54 to 5600 46 mph

email me if u have any other questions
i am afraid i am gonna hurt the alpha 1 at those rpms but not sure also am thinking of a turning point legacy do to the vent holes to give me that hole shot just in case i ever wanted to pull up a sing ski not sure i ever would but @ least i think the holes would help me get that log of a boat out on plane. but i will listen to any prop name and type u sugest

thank you for any help
joey
 

hwsiii

Commander
Joined
Jan 25, 2009
Messages
2,639
Re: Does this prop seem right?

Gunner1, it is VERY obvious from his post, he is NOT sincere, just an A??.


this post is for HWSiii
i dont know how to get up with you so i am trying to reply to this post. ok so i have researched you and your advice. i have heard alot of wind blowing Translation: HOT AIR from alot of lips aver the winter but by all means i have read all and i mean all your post. i have come to the conclution that u may be the only person on the face of the planet who can help me.


Sorry gunner1
I have asked him for his phone number in a private message so I can HELP him.



H
 
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