F150 prop

[MNBassn]

I bought a F150 for my Ranger 481v. This is an 18 foot boat. Dealer put a 19 pitch prop on it. Boat is very quick, but I have only run the motor to 5000 rpm’s because I am still in the break in period. My question is: looks like my top end is only going to be about 50 mph. Should I ask for a 21 pitch, or will that be too big for this motor.

[PSM207]

What speed do you achieve when you spin the F150 to 5800 or above? I owned an F150 for over 15 years and spun it near 6k often. It's a great engine and runs strong in the upper rpm range.

[MNBassn]

I have only run about 5200-5400 range. Getting mid 40’s. Thought I would get mid 50’s minimum

[Musky Mike]

You really won't be able to get prop pitch until your break in is done and you can get a WOT run at max trim. If it just barely hits the rev limiter (with a normal load 1/2 of gas), you can have the prop reworked to bring the RPMs down. If it is all over the rev limiter while the speed is still climbing, you will need to pitch up to a 21 prop (or maybe 23).

[PSM207]

My F150 rev limited at 6150 and I spun it at 6k+ many times. What max rpm have you been able to achieve thus far?

[MNBassn]

I am almost done with my 2nd hour of the break-in. Ran it up to about 5400 and thought I shouldn't push it any harder. Will be gone next week, so will be finishing the break-in and then gonna test the top end.

[MNBassn]

Finished the 2nd hour breaking and pushed it wide open. Just under 6000 rpm until I trimmed it up and then ran about 6100 rpm. Top speed was only 50 mph on my GPS. Thought I should get at least 55. Should I look at a 21 pitch prop?

[PSM207]

Your hole shot will suffer with the 21.

[PSM207]

What is the make and model of prop on it now? I'm assuming it's a 3 blade of some sort?

[MNBassn]

It is the Yamaha Reliance Series

[PSM207]

Does the dealer have 21p you can try?

[MNBassn]

That was my thought. Gonna stop there tomorrow and check. Thanks!

[Musky Mike]

Try asking on the Ranger board if anyone is running the same combo as you. There are so many different props, and it not apples to apple on pitch. When I had my F150 on a 18.5' Stratos, Tempest and Trophy props ran good, with the smallest PVS plugs (23 pitch). Once you find a prop that runs good, you can send it to Mark, to have it reworked to improve it. Like PSM207 said, try a 21 pitch and run WOT for a really long run and see if you can get to rev limiter, if you're between ~5800 and just into the limiter, that would be a good starting to have the prop reworked. Basically, if you find a prop/pitch that will run 6000 rpm WOT plus or minus 200 rpm, you should be able to have it rework to get where you want it.

[wisranger]

Try a 21” pitch Yamaha pro series prop. Often referred to the 21-m.

[Musky Mike]

Try a 21” pitch Yamaha pro series prop. Often referred to the 21-m.

The Pro Series is a good prop, but it was designed for two-strokes and vents are too big for a four-stroke. I ran one on my F150 and had to epoxy the vents closed, and then drill small holes in the epoxy for just a little bit of venting.

[SteezMacQueen]

It is the Yamaha Reliance Series

I have a Yamaha reliance 21p on a 2003 Skeeter TZX190 (18’8”). I have a 2023 SHO 150 on it now and I had a F150 on it originally. The prop will really get the boat on plane quickly, and the revs are all over the limiter. 6100-6200 @ 55mph gps. I tried a 23 p Tempest Plus and it is very dogish out of the hole, top speed is still 55-56 gps. The revs max speed out at 5400-5500. I just ordered a 22p Tempest plus. I’m hoping that it will still hole shot decent and get a little more rpm’s and higher top speed.

I am certain that a 19p reliance is too small for that boat. A 21 reliance may be good for the boat. You should be able to get to 55 mph consistently with a heavy load and the 21p with a fresh 150hp and 2:1 gearcase.

[MNBassn]

Well, I put a 21p prop on today. It is a Yamaha reliance prop. I only have about 3 hours on the engine. Wide open, I could get 5800-5900 rpm and 51.5 mph. Little drop in rpm’s and 1.5 mph increase. I am hoping more hours on the engine will improve the perf. Opinions/ideas?
Thanks!

[21XDC]

21P Tempest Plus or 22 Bravo1 FS or Marks Razor4 XL.