Prop Help, Speed issue?

[Maverick7]

I just purchased a 2004 Crownline 180 Bowrider. This is the first bow rider I have owned, as well as the first I/O iv owned. Spent my entire life on fishing boats with outboards, decided to trade it in for something more suited for the family.

Anyways, the boat has a 4.3L Mercruiser v6, 1:81 drive ratio. The prop currently on the boat is a quicksilver black diamond with a 17p. No idea on the other measurements, the side of it says QA1912X if that means anything?

Top speed on this boat with two people in it (roughly 350lbs, total) is 38 mph. I reach that speed at around 4800ish rpms and then hit the rev limiter somewhere around the 5000 mark. I feel like the boat should have more speed than 38mph, but maybe I am wrong. Just wondering if the speed is due to the prop or what the cause may be. The boat will mainly be used for pulling kids on a tube, wake boarding, etc. So a hole shot is more important than top speed, but even with that being said I would think the boat would move faster than what it does, but maybe I'm completely wrong.

So my questions are...

Does the speed seem correct with the current prop?
What prop would give more speed, but still allow for a good hole shot? (If thats even a possibility)

Thanks!

 

[WesNewell]

You can't have it both ways with the same prop. Want speed, increase pitch. Want power, decrease pitch.

 

[jimmbo]

Boat might have a hook, might have a few hundred pounds of Water in its Foam.

You say the top speed is 38 at 4800 rpm. but then you say the rev limiter kicks in at 5000, so how fast is it going at 5000?. If it is hitting the rev limiter, I would go up 2 inches in pitch and see what it tops out at. Your acceleration will be slower. If the engine is no longer hitting the rev limiter, and you are near 4800 rpm great. You will likely have a higher top speed

 

[Maverick7]

Sorry for the confusion, the top speed is 38 mph at 5000rpm, when it hits the limiter. If I bring it back down to 4800 (the wot on the engine says 44-48rpm) I’m doing about 35.

when you say the boat may have water in the foam, are you referring to the foam in the upholstery or someplace else I should be looking for?

I completely understand you can’t have it both ways, I was more referring to whether that speed seemed accurate with the current prop.

just throwing this out there, If I currently have a 17p 3 blade prop, And switched to a 19p 4 blade prop? What could
i expect? Part of me thinks that would keep the hole shot strong, and give it a little more speed, but then again I’m not an expert so it’s just a theory.

 

[WesNewell]

38 mph at 5000rpm is a 14% slip. That's not bad depending on load. Switching to a 4 blade19" would bring your rpms down to ~4600 at wot, which would give you a top speed of 40 mph with the same 14% slip.
https://www.go-fast.com/Knowledge-base/Find-your-prop-slip/Prop-slip-calculator

 

[QBhoy]

Hi
a 3 blade 19”-21” is your usual fitted to such a set up. That will see you just right. Then enjoy

 

[Murfalert]

I have the same boat that goes over 50 (barely) but doesn’t have great holeshot and takes too long to plane. That’s all with a 14 3/8 x 21 stainless with cupped blades.
I may be interested in more what your 17 does.
Murf