Prop questions

[ReelyNauti]

Ok just a general question....

Anyone here with 2820 please respond unless you know/had a 2820 or know someone that does...thanks so much...

OK pulled the props and took em to the shop......

i am told they r 21 pitch high performance props....

i achieved 49 mph at 5900-6000 rpm in a 7-10 mph wind in light 1-2 ' chop last fall and thought it was pretty good?

so feed back on my stainless steel 21 pitch 17 props?

i think im ok but didnt know i had HP props is this normal or did i get lucky?

lucky 4 me also means an extra 30 $ per prop for balance and polish..lol :shock: :shock: :shock: :shock: :shock: :shock: :shock: :shock: :shock: :shock: :shock:

 

[BradV]

If you are spinning a 21 pitch prop then you probably have a smaller diameter prop. With a 19 pitch I was able to get 53mph with 6100 RPM. So that means you have a lot of slip. go to prop gods website or any other place you can find a prop calculator and see what slip % you get. If you are spinning a 21 at 6000 rpm then with 10% slip you should still be going 53. Id consider getting a larger diameter prop in a 19 pitch that will help you if you have trouble staying on plane at slower speeds or if you run heavy all the time. Any idea what kind of prop? are they the stainless yamaha props or the black painted ones? swsII? But in the end if youre happy with what you have then 1k is a lot to spend.

 

[ReelyNauti]

yes they r yammie stainsless steel...

im going to get the specks and post next week or so ....

Brad you had 19 pitch, what size: 17"???

 

[BradV]

I had the Rev 4 which was a 4 blade that was 19 pitch and 14 5/8" diameter. I also had real good luck with the Mirage Plus which was also a 19 pitch but was 15 1/4" diameter. If you dont feel like you need the stern lift the Mirage was faster by about 3 mph. but i prefered the handling and ride with the Rev so i stuck with that.

 

[BradV]

Judging by the fact you can spin the 21 pitch and that it has an R stamped on it I would venture to say you have the reliance series of props which would mean that you have a 13 3/4" diameter which is pretty small. The reliance props are usually put on boats with 150s because of the smaller diameter.

 

[ReelyNauti]

ok i have some home work to do

when i pick up the props ill do some more investigating....and then next week ask a bunch more questions ..
and thanks so much

 

[ReelyNauti]

more info / updates

The props i have are Yamaha high performance

21 pitch 3 blade 14 7/8

with two hundred gallons of fuel and two passengers in 10 mph winds and 1 ft or light chop in open ocean i am at 5800-6000 rpm at 49 mph....................REMEMBER its a 2820 from 06 it only has twin 225 NOT twin 250's

I have spoken to a member here he has a 2008 2820 with twin 250's with two passengers and 150 gallons he is at 5600 -5800 53 mph....

so the question is am i in the range???

my rps's seem to be
the boat is quick as all hell out of hole and the ride is good

here is a picture or two of props...MAN o MAN are these things solid as a rock and thick all over nice!!!