Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: prop/speed on 86 revenge-175 johnson
Posted by hrnhunter on 07/03/09 - 3:55 PM
#1
I'm getting about 30 mph right now with unknown aluminum prop. I was considering going to a ss, any suggestions on size and pitch? What kind of speed can I expect?
Thanks
Posted by Derwd24 on 07/03/09 - 4:04 PM
#2
Take a look on the prop hub, in the round spot right behind the prop nut, sometimes the dia and pitch are shown there. Do you have a tach?
Posted by Phil T on 07/03/09 - 4:19 PM
#3
As Dave said, we will need more information:
1986 Revenge ...(What length?)
Propeller brand and size (diameter x pitch)
Tach RPM's at WOT
Speed measured by GPS
Load (fuel, gear, passengers)
Water and wind conditions at the time observations were taken
Engine height
All these answers will help us get you dialed in.
Posted by hrnhunter on 07/03/09 - 9:07 PM
#4
22 foot revenge- outrage hull with a cuddy. I found a 15x17 on the hub plus a serial number, but no brand. I hit the thirty mark by gps under optimum conditions, no wind, light load,35 gallons of fuel, two men and a 60 pound bluetick coonhound, with the tach running about 48-4900. If I'm pushing a slight head wind it's more like 27 or 28. also the gps measures sm/h, not sure what the s stands for? not sure what to measure for engine height?
Posted by Joe Kriz on 07/03/09 - 9:13 PM
#5
I owned a 1989 22' Outrage Cuddy. About the same weight of your Revenge.
I had a 1999 Evinrude 175 hp on it and the boat would do 40 mph...
The prop was a
14 1/ 2 x 17 Pitch - Renegade Offshore 4 Blade Prop
I am not saying this prop is the right one for your motor as we don't know the year of your motor.
As far as mounting height. It is measured by which hole the mounting bolts are installed in the engine bracket.
Mine was mounted in the second set of bolt holes from the top which is called the second hole up...
All boat can vary slightly due to many other reasons.. Therefore, each boat needs to be setup individually for optimum performance.
Edited by Joe Kriz on 07/03/09 - 9:18 PM
Posted by hrnhunter on 07/03/09 - 9:45 PM
#6
I also have a 28 horse johnson kicker motor on it and I think both motors are original, "86, It seems like I read that somewere but I can't find it right now. The main motor is mounted in the top hole. I'd love to get 40 out of her but maybe this old motor is too tired to do it. any suggestions on what I might try?
Posted by Joe Kriz on 07/03/09 - 10:04 PM
#7
Your motor is definitely mounted too low.
I would start by raising it up one hole to begin with.
You might even end up going up two holes with the motor.
Other members here can probably recommend a prop for you.
Posted by hrnhunter on 07/03/09 - 10:11 PM
#8
Thanks Joe, I'll try that. What can I expect if I go too far or not far enough?
Posted by RevengeFamily on 07/04/09 - 4:06 AM
#10
hrnhunter wrote:
with the tach running about 48-4900. If I'm pushing a slight head wind it's more like 27 or 28. also the gps measures sm/h, not sure what the s stands for?
I believe at WOT that engine should be turning between 5- 5500 rpm. Your GPS gives you the option for speed readings in either SM/H (statute miles) or NM/H (nautical miles).
Posted by Eri on 07/10/09 - 10:12 AM
#11
Just an FYI. After consultation with a well known Johnson/Evinrude dealer, at least for the 18 Outrage/Newport models, he recommended the cavitation plate up to one inch above keel.
Posted by hrnhunter on 07/11/09 - 10:08 PM
#12
Thanks, I moved my motor up two holes, putting me at the third hole up with 1/2 inch above keel and gained 2 mph, I think I'll try one more, putting me around 1 and 1/4 inch above keel. I was thinking about going to a 15x15 prop, I appreciate any advise anyone might have for me on this.