Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Prop sizing help needed.

Posted by DonavonMn on 07/09/12 - 10:47 PM
#1

I knew before I put my 1974 custom 16' in the water the prop wasn't even close to matching my boat, but it was enough for a test drive to find any potential problems with the boat. My motor is a 1996 Evinrude E90ELED, the prop is an aluminum Michican Wheel 14" x 11. The motor was from 35' steel hulled house boat, it was main motor from a set of twin 90's. I think I was at just under 4k just to plane out, no where even close to WOT and I was at 6500 rpm. I didn't have the GPS with, but I'm guessing I was doing 35-40mph max.

My whaler will mainly be used mainly on the upper Mississippi River for river cruising around the St.Paul area, the current is strong and the water moves fast. So I'm a little more concerned about have a little more torque than top speed. It will also be used on the St.Croix River, which is the first major tributary for is Mississippi. The St.Croix much wider,deeper and slower than the Mississippi up here, you will see anything from canoes to 65' cabin cruisers. So I do need a little top end also.

From what I've been reading 13" x 17 pitch is about what I'm looking for, am I close or way off?
Thanks,

Don

Edited by Joe Kriz on 07/09/12 - 10:51 PM

Posted by Joe Kriz on 07/09/12 - 10:55 PM
#2

See this new article we have which will continue to have more info when we have time to add it...
http://www.whalercentral.com/articles...cle_id=108

6500 RPM is way beyond redline I believe for that motor.

Posted by Tom W Clark on 07/10/12 - 8:12 AM
#3

Don -- You are close but it depends on exactly what model of propeller you are talking about.

The Evinrude/Johnson 90 on a 16'-7" Whaler usually makes good use of 13" x 17", 13-1/4" x 17", 13-3/8" x 17" or 13-7/8" x 17" OMC/BRP propellers from the aluminum, SST, SSP or Viper lines.

If you go with a Stiletto/Turbo/Yamaha prop, you want the three blade stainless steel model (Advantage/Turbo 1/Performance Series) in the 13-1/4" x 15" size.

Posted by DonavonMn on 07/10/12 - 9:43 AM
#4

Tom,

Sorry, I should have stated I'm not looking for a stainless prop at this point, I'm just looking to get where my boat runs in the correct RPM's at WOT for this season. Next year I want to pick a nice stainless prop and then use the one I buy this year for a spare prop. From my limited understanding of props and what I've read here, you generally just look at just changing the pitch and not the diameter of the prop. The only reason I asked about going with a smaller diameter is because of the original application of my motor, looking at props on Michican Wheel's website; a lot of the 14" come in 9 and 11 pitch. So I'm kind of assuming the original owner went with a larger diameter prop to move more water volume because of the original application, pushing a steel hulled houseboat.

Mainly I'm pushing way too many RPM's right now, I'm more worried about not blowing my motor than anything else. I didn't run the boat it at 6500 rpm for too long, it was more of a suprise than anything else. After it planned out I wanted to open it up to see what it would do and the rpms jumped up quick and boat launced forward and I shut it down quickly. Just from the one time I got on the throttle; the rpms were too high for the speed and how much throttle was left.

Thanks,

Don

Edited by DonavonMn on 07/10/12 - 9:47 AM

Posted by Tom W Clark on 07/10/12 - 9:55 AM
#5

Obviously, a prop for a houseboat is not going to work on a 16'-7" Whaler. At all.

You shop for propellers by model, not just size. There is far more to propeller design than just pitch and diameter.

But why fool around? Just buy a 13-1/4" X 15" Stiletto Advantage. I have yet to find a better prop for the classic 16'-7" Whalers and you will be very hard pressed to find a stainless steel prop for less money too.

Posted by thegage on 07/10/12 - 11:09 AM
#6

Donavon, I have a similar engine (1992 Johnson 90) on my 16 SL, and I run the 13-1/4 x 15 Advantage prop Tom recommends, which replaced an OMC 13-1/4 x 17 aluminum prop. The boat is a bit heavier than yours, with a differet profile, but the propeller has plenty of torque. The boat jumps onto plane, cruises at an easy 3800 rpm, and tops out at about 5300 rpm at WOT. The Stiletto will run a bit more than double an aluminum prop, but you won't regret spending the extra money.

John K.

Posted by DonavonMn on 07/10/12 - 11:07 PM
#7

Thanks, a Stiletto Advantage 13 1/4" x 15" will be the prop I'll be running next year, it would be a good prop for the more recreactional St.Croix River. But this year funds are getting tight and I still need to buy a Bimini top, and a couple of 12 gallon tanks. I've also been told by a lot different people that run this part of the Mississippi, that it's pretty hard on props.

What I really need is to be able to walk into someplace like Cabelas and grab two props off the self, so I can bring my boat out this weekend. Would I be safe with picking up something like what came on gage's motor, a 13 1/4" x 17"?

Thanks,

Don

Posted by Tom W Clark on 07/11/12 - 6:45 AM
#8

Well, that's two reasons to not buy anything except a good stainless steel prop. Stainless steel is five times as strong as aluminum and will last much longer. If you buy aluminum prop and use it where it might be damaged, you just be buying another one soon, and then another and another.

This is why stainless steel props are actually less expensive in the long run. Not only they do they offer better fuel mileage, they last much, much longer and will be less likely to leave you stranded.

Also, if you buy a cheap prop now and a better one next summer, you've spent money on two props instead of just one. If you want to save money, just buy a good prop now and be done with it.

You'll spend $150 for a crappy aluminum prop and a good stainless steel one will only cost $250. Why spend $400 when you need only spend $250?

Posted by dgoodhue on 07/11/12 - 6:51 AM
#9

If your looking a cheap spare I will sell you a 4 blade composite 17p prop that will work. I would buy the Stilletto for your primary prop.

Posted by DonavonMn on 07/11/12 - 7:48 AM
#10

I didn't realize a stainless prop could be found for under $300, I did a quick check on-line last night and I and most were around $400. I'll do a little price shopping the next few days. I was really hoping to run my Whaler this weekend, but it looks like I'm bringing the Zodiac out instead.

I'll do my best to find a 13 1/4" x 15" Stiletto this week or the next.

Thanks for all the input and advice. I'll also try to get some pics of my 16' custom and my redone(but sold) 13' Sport.

Don

Posted by Tom W Clark on 07/11/12 - 8:00 AM
#11

If anybody pays more than $240 for an Advantage 4.25, they're paying too much.


Posted by thegage on 07/11/12 - 10:23 AM
#12

Dan's Discount Props for one has them for around $250; Overton's for another.

John K.

Posted by rvschulz on 07/11/12 - 12:08 PM
#13

and while a lot of people distrust eBay - i have routinely bought and sold props there - my current OMC 13 3/8x17 prop on my MOntauk was $75 plus shipping for stainless ... shop hard.

Posted by Tom W Clark on 07/11/12 - 12:12 PM
#14

Dan's has amazingly good pricing. With the shipping the Advantage 4.25 is only about $265 delivered complete with hub kit.

Overton's is about $330 delivered with hub kit.

Still, I know where to get them for $240, delivered with the hub kit.

Posted by dbcollen on 07/11/12 - 12:20 PM
#15

"Still, I know where to get them for $240, delivered with the hub kit."

Tom,
Are you going to tell us where, or is it a state secret?

Posted by Tom W Clark on 07/12/12 - 7:53 AM
#16

dbcollen -- I can get you that prop.

Posted by dbcollen on 07/12/12 - 8:18 AM
#17

Tom

I appreciate the offer, but I don't need it. The original poster may though. I was just commenting because it you kept mentioning you knew where to get it for $240 but never said where. It wasn't clear that you were offering to get them from your source for people. It reminded me of an old joke, "How do you keep an idiot in suspense?...... I'll tell you later..... :) "

Just to be clear, I an not calling anyone an idiot, just telling a joke.

Posted by Tom W Clark on 07/12/12 - 8:32 AM
#18

dbcollen -- I am a PPI dealer but I do not like to promote myself because it might make my propeller recommendations appear as a sales pitch; they are not. They are honest recommendations based on my experience fitting propellers and helping my Whaler brethren out, time after time after time.

I don't really care where anybody buys their propellers but I do want them to make the right choice so they can get the most out of their boats. The propeller is the single most important piece of hardware on any outboard. It has to be right.

Posted by dbcollen on 07/12/12 - 8:46 AM
#19

I really appreciate all your advice, I plan on getting your opinion on ss props for my twin mercs when I save up enough money.

Posted by John Fyke on 07/12/12 - 9:48 AM
#20

Tom W Clark wrote:
dbcollen -- I am a PPI dealer but I do not like to promote myself because it might make my propeller recommendations appear as a sales pitch; they are not. They are honest recommendations based on my experience fitting propellers and helping my Whaler brethren out, time after time after time.

I don't really care where anybody buys their propellers but I do want them to make the right choice so they can get the most out of their boats. The propeller is the single most important piece of hardware on any outboard. It has to be right.


Tom, that is a very honest and stand-up comment. It's nice to have folks like you around.