Prop - How do I know what size?

[TrepMan]

Gang - Motor is a '99 Mercury 115hp carb'd inline 4 cylinder. I've been looking to go down a pitch in prop and go to a 24p to see if that gets me the extra 200rpms I need to get closer to 5250rpms, and as a backup (or make my Turbo a backup). I see lots of different sizes (13 inch, 14 1/2, 14 1/4...) and mentions different "splines". How do I know what I need? I will probably, if Tim and I can't work a deal on his ballistic, will ebay a prop, don't want to buy the wrong one.



Oh and some mention "hubs"? Someone educate a brotha!

 

[Christopher Laurencio]

Look at the Mercury website, it's a good start, they have an interactive prop-selector.

 

[TrepMan]

Chris - Just did that, it confused me more since it recommend both a 13.5 diameter and a 13.75 diameter prop. I guess I assumed my prop shaft require(s) a specific diameter. See I am totaly clueless!!



But I am catching WAY more fish out of my Nitro!!

 

[Jim B]

Honestly Trep if you are 200 rpm away from max i wouldnt mess with it as long as the holeshot is acceptable and its not lugging. dropping an inch in pitch to get those 200rpm isnt going to get you much on top if anything, also from what i hear those 115's dont like to be over revved one bit.



The reason you see different diameters is because of the different blade configurations. If you are going to run a merc prop decide on if you want the 3 or 4 blade,the prop selector gives you the part numbers that fit your motor. If you are going to run another brand you should be able to dig up what part numbers from that brand fit.

 

[Christopher Laurencio]

How about a Hustler Prop, at one time they made them look like SS instead of alum, but now they are just black, but you could get one of these, if you don't like it you could then return it :huh:.




http://www.basspro.com/servlet/cata...arClassCode=2&hvarSubCode=6&hvarTarget=browse

 

[Christopher Laurencio]

And Trep you might loose some "bite" and not have the better handling steering at low speeds with a diff. pitch. Just a thought, does the end justify the means.

 

[Bruce Freeman]

Whats on the boat now?



BF

 

[Tim m]

Trep, Here is what I have learned based on all the props i have tried on my boat like yours...With my Trophy4 blade i dont get over 5000,with my 24 Ballistic i dont get over 5000,,With these 2 props i do get great top end more with the Ballistic now with the plugs,top end drops of 2-3 mph with the 4 blade...I bought a Power tech prop from Pat and he said it was a 24 or 22..Must have been a 22 becouse my rpms went to 2250-2300 but i lost a few mph on top end.....Before i had the plugs put in the ballistic I had blow out problems,Now it really bites and i have a rooster tail w, little boat in the water with a little chine walk even...Felt really good going down the lake...I never realized how much those plugs would help out...Its like i have the perfect set up now finally,seeing how i am getting rid of the boat.......

 

[TrepMan]

Pat - Does the sline have to be 13.5 inches? Stupid over here, but the Merc site recommends both a 13.5 and 13.75 diameter props?? I remember there being something about a "hub", is it that my prop shaft is 15 splines and 13.5 diameter but a larger diameter prop will fit if it has the right hub, or is the diameter the external inches around not the inside of the prop??



I know the ballistic that Tim has will fit, and I know the Trophy my buddy has will fit (as both were put on/off a 115 merc) but if i find a great deal on ebay, how do I tell? Is it just 13.5 and 13.75 diameters i'm looking for?

 

[Marty Klein]

Trepman: Reading about you trying to squeeze more speed for your 600 series Nitro is like watching a VW guy trying to compete with Vettes [:lol:] and I've seen your picture--you are so far left of being a brutha! :lol: ...

 

[TrepMan]

Marty - Its a 700 series!! :lol: So I gotta squeeze ALL I can with my skinny arse driving!!! LOL



Actualy my biggest issue is I want a backup prop, now that I can run in the 50's I tend to go much farther from the ramp, and if I rip a prop, I want a backup.



And hey, if ya can't tinker with your boat, why have it!!

 

[Marty Klein]

Mea culpa on the "600" remark.

 

[TrepMan]

Marty - no problem dude, heck until I got this Nitro I though all you 'glass' guys were looney for even spending ANY money on a jackplate, different props, load/weight balancing...!!!



As Pat Goff told me a few months ago "you got it BAD!!!"

 

[Marty Klein]

I don't have it that bad. If someone asks me the setup on my 750, I say there is a motor bolted to the back and yes, it does have a propeller. :lol::lol:



By the way, I recommend a stainless propeller. Why? Because I banged my original equipment prop twice. I replaced it with a stainless prop and haven't hit anything since. There is nothing more exciting than flying down the lake in 30 feet of water and hitting submerged timber.

 

[TrepMan]

Marty - OUCH on the "flying down the lake in 30 feet of water and hitting submerged timber."



I sit at my desk all day staring at a computer monitor, tweaking my boat is my relaxing time when i'm not on the water.



So, anyone else, do i need a 13.25, 13.5, 13.75 diameter or is that not have anything to do with making it fit on the propshaft? I've seen 14.25 diameter props on ebay, they don't always say which motor they fit.



Pat?

 

[Tim m]

The splines is what is important more so than the diameter of the prop itself...And we have the small hub as they call it...My Triton has a Tempest with the Big hub..Hub meaning the size of the props roundness or barrel that blades are attached to..

 

[TrepMan]

Pat - You can call my boat a dog, heck my fishing partner calls ME a dog!! !LOL



OK i think I got the spine, diameter and pitch stuff, 6 years later!! LOL



Now Pat, what are the "wrong" props for a 700lx 4.5 inch vance manual jackplate, 115 merc Carb'd Merc, currently running 5000rpms WOT on a 25p Turbo 3 blade, prop shaft 5.5 inches below the pad, water pressure over 15psi at WOT.



MAN This is cool!! LOL



Oh and a REALY skinny arsed driver!!! LOL I know, I know... Tune her fully loaded!! LOL

 

[Bruce Freeman]

Start with "Now Pat, what are the "wrong" props for a 700lx 4.5 inch vance manual jackplate, 115 merc Carb'd Merc, currently running 5000rpms WOT on a 25p Turbo 3 blade, prop shaft 5.5 inches below the pad, water pressure over 15psi at WOT" (5.5 inches below pad)? is that number right?

BF

 

[Tim m]

Trepper,Try sending your prop off and pay 30.00 for the plugs,they will help you...I have been where you are about to go and i hope you have good nerves....If you have your rig running good then dont mess with it....

 

[TOMMY RICH]

13 1/4 x 23P would be a good start Trep...I'd try Powertech or Hustler.

Pat's right...you may gain a couple MPH but, it may also really improve preformance as with mine. It corners 10X's better and JUMPS on plane faster than you can say it

 

[TrepMan]

Bruce - Yup 5.5 inches below the pad, i had it up to 4.5 inches below the pad this weekend and lost about 4 mph, so dropped her back down. And sorry it's a 5 inch set back, not 4.5.



OK i understand the size, diameter, width and spline now, thanks gang! In a couple of weeks my buddy will let me try the 24p 4 blade and i'll post my results.



Anyone got a different 23 or 24p in north Atlanta they want to "lend" me to try??

 

[Aaron Scott2]

Anyone else wishing they had Pat G. as their neighbor?

 

[TOMMY RICH]

I dunno:lol:

 

[Bruce Freeman]

Thats OK Aaron you got me and I read everything he writes 10 times then add it to my log book.............



BF

 

[Steve Rizza]

Trep,

Just turn your body sideways at WOT. Should be good for a few MPH !!



That boat scoots pretty good as is. I'd buy one of those cheap composite props for a spare, and run 'er. Spend the extra money on some thing you could put to good use.



Steve

 

[TrepMan]

Steve - "Just turn your body sideways at WOT. Should be good for a few MPH !!" BBWWWAAAAAAA



I got a local buddy who's out of town but back in a week or so, said he's got a few props for me to try, good used ones, will make me a good deal if I want, so i'm gonna hang a few weeks.



How's the Tracker running with those fancy Matrix LCDs???



Man i need to FISH!! And I fished last Sat and Mon night!!! Can't hit the bass for a week, mothers day weekend and all, but I am getting Eli and a neighboor girl out for some crappie on Sat if the weather holds, why my oldest goes with her brother to a chess tourney.



you GOTTA get some vacation time and join us on Cumblerland with Sim, i'll even brew some more beer if you bring the Tin Iron City bottles and we'll swap a case!