Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Prop Survey - 16/17s with OMC 88/90 V-4s
Posted by Bo Neato on 07/30/09 - 11:13 AM
#1
I have a 1997 Evinrude 90hp SPL (V-4) with the OMC 14x17 aluminum prop. I'm turning up to 4800 rpms after playing with the trim a bit. I'm guessing a weight of about 1700-1800 pounds with two adults and 20 gallons of gas, top end speed is unknown as I currently have neither speedo or GPS hooked up. Porpoising is minimal and easily correctable with a bit of throttle manipulation.
The prop is a little flat on the edges from contact over the years but not in bad shape. I found another identical prop NIB for a good price, so I'm picking it up. I'm not expecting a big difference when I swap the screws, I just thought it was a great opportunity to have a decent spare on the cheap. I'm not horribly concerned about increasing speed or mileage, but am very curious as to what other are propping this setup with. I wouldn't be opposed to picking up another prop and using the new OEM as a spare if I knew it would make a huge difference.
So, to make a long story short, what prop are you 16/17 + SPL guys using and which holes are you mounted to?
Posted by Jeff on 07/30/09 - 12:03 PM
#2
My 1976 Newport has a 1974 85hp Evinrude. Here is what I have for prop data.
Day One:
I ran the boat on calm water with very light wave action. The air temp was in the low 60's and all that was on the boat was myself and about 16 to 18 gallons of fuel. The was no wind and the all the speeds were measured on a GPS. The motor on the 1976 Newport is a 1974 85-HP Evinrude Starfilte turning an aluminum OMC 13x19 prop, and I run it trimmed a ways up so the bow is high. Here are the numbers:
2500: 16.3mph
3000: 22.2mph
3500: 28.8mph
4000: 34.5mph
4500: 38.4mph
4650: 39.5mph WOT
Day two:
1976 Newport 1974 85-HP Evinrude Starfilte turning an aluminum OMC 13 1/4" x 17 OMC Aluminum prop, ran trimmed a ways up so the bow is high.
2000: 7.6mph
2500: 9.2mph
3000: 15.9mph
3500: 22.1mph
4000: 26.7mph
4500: 30.1mph
5000: 33.6mph
5400: 35.3mph WOT
Edited by Jeff on 07/30/09 - 12:04 PM
Posted by bruser on 07/30/09 - 7:11 PM
#3
1977 montauk with 1996 johnson 90 (60 degree) motor. Its truninga 13.5 X 19 stainless prop.
WOT is 4900 rpm, 38.7 mph ( gps). It was mounted in the top hole (4100 x 35.2 mps ) then moved up to the third hole. will not porpoise at any speed now.
Posted by Tom W Clark on 07/30/09 - 10:39 PM
#4
The usual prop for a Montauk with an OMC 90 is one of the 17" pitch SSTs or Viper.
The 13-1/4" x 15" Stiletto Advantage has become very popular as well.
We can see from bruser's post that a 19" is too much as both his speed and RPM are held back.
bruser -- Switch to one of the aforementioned propellers and see if you can get your RPM up. 4900 RPM is way to low for a motor that redlines at 5500 RPM and on a boat that should easily go 45 MPH if it is not too heavy.
Two of the three Montauks I have owned were powered by 90 HP Johnsons. They were both equipped with 13-3/8" x 17" OMC SST propellers and did about 45 MPH at 5500 RPM.
Posted by bruser on 07/31/09 - 7:02 AM
#5
Tom:
Yes, thanks for the suggestion, the prop came with the boat when purchased. My focus has been getting the motor height correct. Now I can fine tune the prop selection. I'll take your advise.