Which hifive prop pitch for my boat?

[madman2021]

I've got a 1986 glasstream 17 foot with a mercruiser 140. Currently running a 19P alum 3 blade for pulling and heavey loads, but a 21P SS 3 blade for bass fishing. I was told with a hifive prop I can get the best of both worlds, low end and top speed. My ? Is which pitch of a hifive prop to get? My boat struggles to plane with a 21P and tops out at 47 mph on the gps.

 

[Bondo]

Re: Which hifive prop pitch for my boat?

My boat struggles to plane with a 21P and tops out at 47 mph on the gps.

Ayuh,.... At What rpms,..??

I serious doubt a Hi-five is your answer... It's more of a watersports prop...

 

[madman2021]

Re: Which hifive prop pitch for my boat?

Don't know. My tach is broken.

 

[Bondo]

Re: Which hifive prop pitch for my boat?

Don't know. My tach is broken.

Ayuh,... In that case, your questions are Unanswerable....

Rpms, at Wot is Critical Info for choosing a prop... No exceptions...

 

[mcastles]

Re: Which hifive prop pitch for my boat?

Absolutely correct, WOT RPMs set the bench mark for your motor under load. However, there is an alternative. Buy a laser tach and monitor the RPMs directly on the harmonic balancer, which is directly attached to the crankshaft. It is a little inconvenient, but laser tachs are very accurate and cheap. I recently purchased one to check my boat tach, only to find my boat tach was reading 300 RPMs too high.

Hope this helps.

 

[madman2021]

Re: Which hifive prop pitch for my boat?

Well I'm getting a new tach soon. My wot rpms factory are 4200-4400. My boat at wot with a 21P Feels like it could hold a 22 or 23P. But I wouldn't be able to get out of the hole. I have a friend running a hifive on his 17 foot bayliner with a merc 140 and he has great pulling power and tops out at 52 on the gps. But we don't know his pitch, the numbers are gone.

 

[boat1010]

Re: Which hifive prop pitch for my boat?

Like the others have said, WOT RPM is the only way to tell about your prop. Once you get the new tach then you will be able to figure out about the pitch of your props. It would be best if you could USE a prop to put on your boat to see how it preforms. It is hard to get the exact one that is good for your situation without trying it out on the boat. Different brands preform different.

 

[Robbabob]

Re: Which hifive prop pitch for my boat?

Well I'm getting a new tach soon. My wot rpms factory are 4200-4400. My boat at wot with a 21P Feels like it could hold a 22 or 23P. But I wouldn't be able to get out of the hole. I have a friend running a hifive on his 17 foot bayliner with a merc 140 and he has great pulling power and tops out at 52 on the gps. But we don't know his pitch, the numbers are gone.

Not sure how you think your boat could handle a 22 or 23P since you are already struggling to get out of the hole with a 21P. Perhaps you are not aware of the performance characteristics that pitch has. If you're not aware, then don't try this at home... we are what you call, "experts"

Your HP to boat weight setup with sluggish hole shot says you need lower pitch. Get the tach readings at WOT and we'll be able to help proper like.

As a side note, the Aluminum prop flexes a lot, so it is odd you'd use it as your "work-horse" prop. I"ve got an idea for the prop you need, but am NOT going to share... we must have WOT rpm before assisting.

Good luck!

 

[j_martin]

Re: Which hifive prop pitch for my boat?

The big reason the high five gets out of the hole good is the ventilation. It allows the engine to spool up into the power band before it bites the water. At speed water flow closes the vents.

I have one (24p) on an XR4, 150 HP on a bass boat, lighter than yours but pretty heavy just the same. When I can it, it'll spool up to 3 grand before it goes anywhere, then it's like a slingshot. Tops near 60 at about 6000 rpm.

When I'm pulling skiers, or taking a heavy partner, I put a lower pitch prop on it.

I'm with the crowd on this one. Guessing prop pitch without an accurate tachometer is a recipe for engine destruction.

 

[Bondo]

Re: Which hifive prop pitch for my boat?

I have a friend running a hifive on his 17 foot bayliner with a merc 140 and he has great pulling power and tops out at 52 on the gps. But we don't know his pitch, the numbers are gone.

Ayuh,... After you fix the Tach, borrow yer Bud's wheel to try it...

After you take it off yer Bud's drive, you'll be able to read the #s, usually found under the Nut....

 

[madman2021]

Re: Which hifive prop pitch for my boat?

Not sure how you think your boat could handle a 22 or 23P since you are already struggling to get out of the hole with a 21P. Perhaps you are not aware of the performance characteristics that pitch has. If you're not aware, then don't try this at home... we are what you call, "experts"

Your HP to boat weight setup with sluggish hole shot says you need lower pitch. Get the tach readings at WOT and we'll be able to help proper like.

As a side note, the Aluminum prop flexes a lot, so it is odd you'd use it as your "work-horse" prop. I"ve got an idea for the prop you need, but am NOT going to share... we must have WOT rpm before assisting.

Good luck!

i know for a fact my boat wont plane with a 22 or 23P, im just using that as maybe a refernce for a 5 blade prop choice.

the reason behind the alum 19P prop being my "workhorse" prop is that i couldnt afford a SS 19P last summer and i needed a lower pitch to pull wakeboarders. so i picked up a used alum for $15 with a good hub. also use the prop when the river goes down so i dont damage my gears or nice SS prop when i hit the bottom. as for the tach, it works, but maxes out at 3200 rpms at WOT so that must be wrong.

 

[madman2021]

Re: Which hifive prop pitch for my boat?

Ayuh,... After you fix the Tach, borrow yer Bud's wheel to try it...

After you take it off yer Bud's drive, you'll be able to read the #s, usually found under the Nut....[/QUOT

weve looked over his prop multiple times. front, back, inside, outside, there are no numbers to be found. its a blank 5 blade prop.