14.5x 14.25 Prop, 5.7 Indmar, 5200 rpm 35mph

[D2Dominator]

Hello all,
I installed this prop at the recommendation of acme, and it knocked nearly 20mph off my top speed? I hit the rev limiter of the engine... which I'm confident is not supposed to happen. Is my experience normal for a 2002 xstar with 3 passengers?

Thanks in advance,
D2

[trunderw]

That seems slow for that motor. Also nice original top speed. I can't even hit 50. I think your pitch may be too low. Maybe up to 17 or 18. Surely the prop folks would know better than me though...

[Jhilly8982]

I just picked up an 04 X-9 with the 310hp engine (same engine as OP) and am only hitting 37mph at 4750 rpms (perfect pass numbers) on stock 12.5x12 4 blade OJ. Was told by dealer I bought it from that this is good for this engine...

Will GPS next weekend.

[jj91]

I have the same boat as yours but its a 2004 with the predator engine. To a certain extent you have to pick your poison...do you want more top speed or to pull stumps? Why are you switching props? I upgraded from the stock (OJ 13.7 x 19.5) prop last year (top speed ~43-44 mph on gps). I was looking for something with better holeshot and could handle the weight better, but also wanted to keep most of the top speed. I talked to a couple guys at ACME and I didn't get a sense they 100% knew what they were talking about until I talked with Jim. He was by far the most knowledgeable person regarding my specific boat and engine that I talked to at ACME, especially since this model has had multiple names (x-star, x2, x1). Prior to talking with Jim I was looking at the 14.5 x 15.5 (2061) prop. He actually recommended the 14.5 x 16 (1593) as he thought with the 15.5 pitch I would be hitting the rev limiter. At times I run 750s in the rear, KBG, IBS, 3-4 people in the boat and it can get up to surf speed without a problem. If you are running a lot more weight than me or even that weight and a boat full of people all the time you might want to go with a lower pitch prop, but even with the 14.5x16 if I'm empty I can exceed the recommended WOT RPMs (4800). I don't like to push it so if I'm pulling bigger footer and need more speed I will run it up to ~4800 RPMs which puts me at ~42 mph (per my gps perfect pass). I could probably push another 1 mph if I let it go past recommended RPMs, but not worth it IMO. If it's speed you are looking for Jim did say said their 14x17.75 prop would most likely increase my speed 1-2 mph over my stock prop, but also provide better holeshot over the stock prop.

If I was you I would ask for Jim when you call ACME. If you ordered the prop direct from ACME you can probably exchange for free. Or call Eric from OJ props. He knows all there is to know about props and is regularly on this site.

[D2Dominator]

I have the same boat as yours but its a 2004 with the predator engine. To a certain extent you have to pick your poison...do you want more top speed or to pull stumps? Why are you switching props? I upgraded from the stock (OJ 13.7 x 19.5) prop last year (top speed ~43-44 mph on gps). I was looking for something with better holeshot and could handle the weight better, but also wanted to keep most of the top speed. I talked to a couple guys at ACME and I didn't get a sense they 100% knew what they were talking about until I talked with Jim. He was by far the most knowledgeable person regarding my specific boat and engine that I talked to at ACME, especially since this model has had multiple names (x-star, x2, x1). Prior to talking with Jim I was looking at the 14.5 x 15.5 (2061) prop. He actually recommended the 14.5 x 16 (1593) as he thought with the 15.5 pitch I would be hitting the rev limiter. At times I run 750s in the rear, KBG, IBS, 3-4 people in the boat and it can get up to surf speed without a problem. If you are running a lot more weight than me or even that weight and a boat full of people all the time you might want to go with a lower pitch prop, but even with the 14.5x16 if I'm empty I can exceed the recommended WOT RPMs (4800). I don't like to push it so if I'm pulling bigger footer and need more speed I will run it up to ~4800 RPMs which puts me at ~42 mph (per my gps perfect pass). I could probably push another 1 mph if I let it go past recommended RPMs, but not worth it IMO. If it's speed you are looking for Jim did say said their 14x17.75 prop would most likely increase my speed 1-2 mph over my stock prop, but also provide better holeshot over the stock prop.

If I was you I would ask for Jim when you call ACME. If you ordered the prop direct from ACME you can probably exchange for free. Or call Eric from OJ props. He knows all there is to know about props and is regularly on this site.

I bought this prop at the recommendation from Jim! I don't really care about top speed necessarily, but I know that if i'm hitting the rev limiter, I've got the wrong prop on the boat. I'll call him back today and see what options I have.

[mzimme]

Different boat, but I run that prop on my 5.7L V-drive, and turn just over 5000 RPMs at WOT, never hit my rev limiter though. I'm doing about 41mph on GPS. This is a Supra 20V. That prop made a huge difference over the stock prop, and I only lost about 3-4mph (that I never used anyway).

[Shaun R]

20mph is a lot of speed to lose, are you sure the prop key didn't fall out when you installed the new prop? Assuming 02 is not spline yet, can't remember exactly when they switched.

[D2Dominator]

20mph is a lot of speed to lose, are you sure the prop key didn't fall out when you installed the new prop? Assuming 02 is not spline yet, can't remember exactly when they switched.

So my boat is an enigma... it has a splined shaft as an 02. I'm thinking it was a transition boat, as MC only had the serial numbers for the engine and tranny, and wanted me to call INDMAR to find out what gear was originally installed. I had a 14x20 prop on before...

ACME just instructed me to try the 1593 14.5 x 16 with a 135 cup, and the local shop will swap it for free.

I'll let you know what shakes out of it.

Apparently the guys at ACME absolutely love the Predator Engine BTW.

-Pete

[Shaun R]

I had the 14x18 and 14x20 on the LT1/slot. The 14x20 idled way to fast for loading the trailer and no wake zones, 14x18 was a great prop for 1800lbs of ballast, im sure you run more. I still hit 48 with the 14x18 and not on the rev limited.

[Upnorth07]

I know our hulls are a bit different and not sure the HP on your motor, but I have the MCX and the factory 14.5 x 14.25 OJ prop.

I get to 5400rpm at WOT and 42-43 MPH on GPS for what that is worth. It gets there quick, too.

Also, when I'm fully sac'd out with 2150lbs of ballast, it will get on plane and run in the 30mphs with this prop.

[D2Dominator]

1593 works well for my use.

I loaded up 750 in each rear locker, 300 in the center. I'll likely need more in the bow, but i'm getting there.

Got up to speed (21.6mph in about 5 seconds) without an aggressive throttle move with two passengers and a rider. I got close to top speed @ 42 MPH with 2 passengers and no ballast.

I have to verify with GPS to be sure, but its faster than I need.

Swapped it for no cost BTW.

-D2