Looking for some Prop help 2400scr 5.0

[viper12161]

Hey everyone,

Looking to re-prop my 01 2400scr 5.0 Alpha one. I have looked all over online trying to find some info, but everything seems to be for the 5.7. Last year was my first year with the boat. Loved her, but just had a hell of time getting her up on plane. I was in the 4,700 range on the tach at full throttle and topping out about 29mph or so. Tach was a little finicky....every now and again it would read like 6,000rpm at 3/4 throttle. A light tap would bring it back down, but clearly it has emotional issues and I am replacing it, so not 100% certain the above numbers are right, but seem correct. I did start dropping down the tabs and that seemed to help a bit, but still seemed way sluggish getting on plane. That is with myself, my wife and my 13 year old son on board. I am looking into getting a 4 blade prop, figuring that would get me some more pop out of the water. I am also replacing the trim tab system, so thinking that should help as well. I am stuck on what prop to get. It currently has a Quicksilver 15x17 3 blade on it. I don't have the luxury of trying a few different sizes as I keep the boat in a slip during the summer, so once she is in, she's in. I have changed a prop on my other boat in the water before, but not something I really want to do again if I can avoid it. I am not looking for a speed screamer. I am just fine with about 30mph or so. I'm out enjoying the water and never really in a hurry to get anywhere. Also trying to see if I would benefit going to Stainless vs Aluminum. Any input would be great!!! Thanks!!!

[donald]

4400 to 4800 RPM is Max RPM engine should rum at. Max speed is not the way to judge a prop, Max RPM only.
You also do not want to run at max RPMs.
Is your engine carbed or EFI, if carbed you only have 220 HP, if EFI you have 240HP,If carbed you are not going to get a hot rod no matter what prop you put on it.
These boats are heavy so small engines have a hard time coming on plane. I have a 1995 2400 with 5.7 carbed supposed to be 235 HP, but past owner replaced the engine and I think it was replaced with a 260 HP and it still is not a hot rod. Mine weaghs out at about 6000 + lbs.
Hope this helps.
Good Luck, and enjoy your boat.
Don

[viper12161]

It's carbed so it is the 220. Not looking for hot rod, just trying to get her to pop out of the water lol. So luke warm rod

[donald]

I know what you are going through as I had one that was just what you are describing.
I would try a 14.5x17p as that will raise your top RPMs a small amount.
I run a 14.5X17p prop and hit about 4500 RPM and 35MPH, I use my GPS to ck speed as all boat speedometers are way off except ones that are GPS driven.
Don

[viper12161]

Thanks! Is that 14.5x17 4 blade? From all the research I have done, 4 blade will definitely help with getting up on plane. My speeds are all through my Raymarine MDS unit. Speedometer seems pretty accurate as well.

[donald]

No it's a 3blade, from what I have read a 4 or 5 blade will git you up and out sooner but you loose top speed.
The only time I get on plane is when I am on Lake Superior as the other lakes get to shallow too fast for any speed above idle.
I usually use my small boat on those lakes.
Don

[viper12161]

Gotcha. I'm willing to trade off some top speed to get up on plane faster. I'm in Narragansett Bay, so plenty deep.

[shrew]

Going to a 4 blade prop is going to decrease max RPM, much like adding pitch. at 4700 you are at the sweet spot. You really have no room to decrease prop size or pitch. Both of which would decrease time to plane.

If you're looking for better time to plane, then you would need to decrease pitch, rather than increase pitch or the number of blades.

That being said. I'm more interested in where the people, gear and cooler is sitting. You more than likely need to move weight forward to improve time to plane. Also, it's a cruiser, not a bow rider or lake boat. It's heavy.

I had a 2800. I used to move the cooler, Honda Generator and roll up dinghy down below in the companionway as far forward as I could get it.

[viper12161]

Thanks Shrew. So I don't generally bring out much gear. No cooler, I use the fridge. With 4 people on board...I am obviously in the front seat with my wife next to me and the other adults on the seats right behind me. All gear and stuff is up in the front cabin. I know she is heavy and under powered. But the reason I want to get on plane is I have just terrible control if it's just plowing through the water. Just does not feel safe if for whatever reason I needed to get up and go. Granted I am coming from an 18' bow rider lol, so could very well just be me still getting used to the new boat.

[viper12161]

But that being said, from what I have read online, the 4 blade prop has really helped people with this same exact issue, so that is kind of why I am leaning that way

[shrew]

Originally Posted by viper12161

But that being said, from what I have read online, the 4 blade prop has really helped people with this same exact issue, so that is kind of why I am leaning that way

Good luck. Your expectation is not within the scope of what I've experienced.

[viper12161]

Well damn lol. Thanks Shrew Still trying to research, and wishing I had just replaced the damn tach last year so I could be sure that it was even accurate. Or I can just tell the family I just need to take it out on my own from now on. Hmmmmm, I may be on to something here lol

[donald]

Try turning the Tach selector switch on back of tach, make sure it is set for 8 cyl and turn it back and forth several times, that fixed mine.
Don