Which prop for a 2520 MVSC with a F225

[052520]

I now have a "19T" Yam. black prop. Its 19 pitch by 13 1/2 diam (rough measured) . Yam's website says that with a 15 1/4 x 17 SWS I should get 6000 rpm @ 42 mph, with the sweet spot achieving 3.27 m.p.g. Right now I get 5300 rpm @ 35 mph (1 person no gear). If i went from a 19 to a 17 wouldn't I lose m.p.h. ? I'm sure someone here has figured out the best prop for that boat. I don't want to blow $500.00 for a prop thats wrong. By the way is a Yam. SWS worth the extra $$ or is only the pitch & diam. important ? Thanks !!

 

[DaleH]

Most IMPORTANT thing on a prop is to pick the right pitch so @ WOT you're running towards the TOP of the MFg're recommend RPM range. The worst thing you can do to an engine is to lug it by running too steep a wheel.

I'm surprised you're running a 19" pitch prop, as every Parker I know with a 225hp, regardless of brand motor, runs a 15" diameter by 17" pitch prop. I'd go to www.Overtons.com and would buy a 15"x17" pitch Stiletto 3-blade SS wheel for a Yam motor. They will exchange it for another prop unitl you get the performance you need.

 

[052520]

the 19t is what came with the boat ? I think i should have had a choice. I see in another thread "getting the boat ready" esfishdock has a 19 pitch on an 2520xl also ?

 

[esfishdoc]

I read this thread because I've often wondered if there was any point in getting a different prop to improve performance.

I also have a prop that at WOT I get to 5300 rpm. From what I've read the max efficiency for the F225 is right at a WOT of 5500 to 5600. When the boat is propped to achieve that WOT rpm the theory is that other points along the power curve are more efficient.

Also from what I've read..... if you have a more efficient prop you can improve your hole shot.....

Will you lose max mph? Maybe...... but with the 2520 XL I never have a need to run more than around 4700 and my sweat spot is about 4400 rpm and 28 mph at 2.5 mpg when the water conditions are right.

What I would want is to try out different props before I buy one..... I'm told that some shops will work with you on this.........

Then there is the 3 vs 4 blade........ ugghhh.....

My prop does a good job...... I'm sure I could get one that would be better.

Good luck.


Richard

 

[esfishdoc]

the 19t is what came with the boat ? I think i should have had a choice. I see in another thread "getting the boat ready" esfishdock has a 19 pitch on an 2520xl also ?

I've just now looked at Overton's site and using thier prop selector system it looks like my next choice would be a 14.25X17....

Looks like I've just added something else to my list..... sheeeesh....

 

[Sow&Pigs]

I'm weighing in here because I'm going through the same decision process myself. I'm running a 225 Opti, and supposedly the correct prop is a 15X17.

What complicates this for me is that my 25MVSC is new to me, and the engine came with no prop (previous owner kept the SS four-blade for his new Optis...bummer) so I have to buy a prop without knowing what I'm comparing it too...

I'm thinking about a 4 blade aluminum, and my merc dealer said with my set-up I should be spinning a 14.25 X 20. Hmmm... :roll:

 

[DaleH]

... my merc dealer said with my set-up I should be spinning a 14.25 X 20 ...

Just remember that you can't compare the pitch of aluminum props to those of stainless steel. With a big heavy boat like a Parker, that alum 20" pitch prop will flex and more likely be around 18" by the time you're done ! FWIW I've tried 3 different premium SS 3-blade props and they all put my OB to 5700 RPMs (max 6K) on a loaded hull, in the Spring with fresh botom paint. A premium 14.5x17" high-cup 4-blade prop put it to 5650 RPMs.

Usually the rule of thumb in going from a SS 3-blade to a SS 4-blade is to drop 1-2 inches of pitch or change the diameter to keep the same RPMs the same. Again ... this is a rule of thumb ... as sometimes props of the same diameter and pitch perform quite differently due to the blade shape (swept profile versus wide "elephant ear type) and the degree of cupping.

You want to get your prop dialed in NOW though, as with the heat of the summer coming, a normally aspirated motor can lose another 200 RPMs of WOT due to the thinner air. If you're low now ... you really be lugging the motor and that's not good. FWIW my brother runs Yummie motors and his dealer always dials them in to within 200 RPMs off of max.

A good prop shop can also add/substract a degree of pitch or cup as needed if you only need to move 100-200 RPMs or so. Best shop for this in the New England area is New England Propeller. Many people also swear by the service of these guys: http://www.midwestpropeller.com/

 

[Sow&Pigs]

Good info Dale.

BTW, I like that hand-over-hand strip in your picture...hopefully you hooked up on something either a) BIG, b) FAST, or c) BOTH