prop for Mercruiser 4.3 V6

asco

Cadet
Joined
Jun 15, 2020
Messages
17
Hi. im currently running an 21P Mirage Plus prop on my Campion 625 VRI 21 feet cuddy. The engine is an 4.3 v6 mercruiser, 190 HP, and an alpha one gen 2 sterndrive. 1.81 gear rotation.

i can only hit, 41/4200 rpm when its fully trimmed. the engines recommend rpm is 44/4800 rpm.

im think about change the pitch on my prop to 19P.
but when i read about the mirage plus prop, it is for V8 block engines with high horse power. Is this just the wrong prop for my setup?
i understand that the mirage plus as more cup and lager surface area, then other models, and that it pr. default lower your rpm.

im currently hitting 41 Mph. in WOT

whats you thought and Experience? another prop og change pitch to gang more rpm.?
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
The mirage is too big and heavy for your package to Turn well. I wouldn’t use this as a base line for going for another pitch prop. Try a more suited prop for it like a laser 2 of same pitch and you should see the rpm and speed rise a little.
 

asco

Cadet
Joined
Jun 15, 2020
Messages
17
The mirage is too big and heavy for your package to Turn well. I wouldn’t use this as a base line for going for another pitch prop. Try a more suited prop for it like a laser 2 of same pitch and you should see the rpm and speed rise a little.

thx. actually i tried an laser 2. But it was cavitation alot in the water, and i didten run well. did run really bad! So i switched back to the mirage plus. It had open pvs holes, maybe that was the course of cavitate.

as i understand, the "plus" ind mirage plus is that the edge of the prop is more cupped . so i was planing to take it to an prop shop, an make them remove the cupped part and go down to pitch.?
 

asco

Cadet
Joined
Jun 15, 2020
Messages
17
no chance that i just could modify the mirage plus prop? drop it 2" pitch and maybee remove cupped edge?
 

Chris51280

Ensign
Joined
Jan 24, 2018
Messages
932
Too heavy prop and the boat is on the heavy side for the engine. I have a 19ft boat and the 175hp V6. I run a 4 blade aluminum 19p prop and hit 4600rpm and 39mph. just for comparison reasons. try to go to a 19p. There is a 20p 4 blade aluminum prop available somewhere. try that. the 4 blade would help you on the low end to plane faster too
 

asco

Cadet
Joined
Jun 15, 2020
Messages
17
Too heavy prop and the boat is on the heavy side for the engine. I have a 19ft boat and the 175hp V6. I run a 4 blade aluminum 19p prop and hit 4600rpm and 39mph. just for comparison reasons. try to go to a 19p. There is a 20p 4 blade aluminum prop available somewhere. try that. the 4 blade would help you on the low end to plane faster too

well currently im running 4100 rpm and about 40 mph with this 21P. okey holeshot and really good middel speed/rpm run. cruise rpm are around 26-2800 rpm with 21 mph.

so i cant be that bad?
 

harringtondav

Commander
Joined
May 26, 2018
Messages
2,442
I think your boat is going as fast as it will. Seems you have just a little too much boat for your engine. You can pitch down to gain WOT rpm, but you'll loose max speed. A lower pitch prop will improve acceleration/hole shot. That's the trade off.
 

asco

Cadet
Joined
Jun 15, 2020
Messages
17
I think your boat is going as fast as it will. Seems you have just a little too much boat for your engine. You can pitch down to gain WOT rpm, but you'll loose max speed. A lower pitch prop will improve acceleration/hole shot. That's the trade off.

yeah maybee. its cuddy so its a little more heavy then an bowrider. Around 3000 lbs in dry.
 

Chris51280

Ensign
Joined
Jan 24, 2018
Messages
932
yup. mine is 2700 dry. what I see is that the cruising rpm is lower than mine. Probably because you have a higher pitch prop. May not be a bad thing but you may also be lugging your engine. Its like driving up the hill with a manual transmission and low rpm with your pedal to the floor where you should shift into a lower gear to have more power and run the engine more efficient. "exaggerated"
 

skuhleman

Seaman
Joined
May 26, 2011
Messages
60
You will like a 19p much better for all around performance
you might even need a 17p depending on how many people you usually have on board
 

asco

Cadet
Joined
Jun 15, 2020
Messages
17
You will like a 19p much better for all around performance
you might even need a 17p depending on how many people you usually have on board

thx.

but will you say that i could take my mirage plus to a shop an get et remaked to 19P?
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
thx. actually i tried an laser 2. But it was cavitation alot in the water, and i didten run well. did run really bad! So i switched back to the mirage plus. It had open pvs holes, maybe that was the course of cavitate.

as i understand, the "plus" ind mirage plus is that the edge of the prop is more cupped . so i was planing to take it to an prop shop, an make them remove the cupped part and go down to pitch.?

That will defo be the pvs holes causing that. Horrible things when they are missing on all but really fast bass boats.
 

skuhleman

Seaman
Joined
May 26, 2011
Messages
60
thx.

but will you say that i could take my mirage plus to a shop an get et remaked to 19P?

You could, whats your boat load normally? I'm wondering if you dont need to drop to a 17 though... i don't know if a 19 will get your rpms where you want them
 
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