Prop size advise

rm2508j

Cadet
Joined
Jun 7, 2017
Messages
27
Hello folks, I have a 1993 regal valanti 176 with a Mercruiser 3.0. I bought the boat used and don’t have the owners manual. Does anyone know where I can find the size of the OEM prop? The redline for the motor is 4800 and the boat does about 38mph with the current prop but if I push it to hard I can over speed the engine. Any ideas are appreciated.
 

TunaFish389

Petty Officer 2nd Class
Joined
Apr 26, 2018
Messages
184
See if you can find what prop you have on it now. It might be stamped with numbers. This will give you a good base line. Go up two pitch sizes and you should be good.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,676
Hello folks, I have a 1993 regal valanti 176 with a Mercruiser 3.0. I bought the boat used and don’t have the owners manual. Does anyone know where I can find the size of the OEM prop? The redline for the motor is 4800 and the boat does about 38mph with the current prop but if I push it to hard I can over speed the engine. Any ideas are appreciated.

Exactly how much is the engine over revving? Also what condition is the current prop, nicks, chunks missing, bent blades, torn blades? As mentioned in an earlier post, there should be some info on the prop so as to identify it.
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
6,782
When I had a similar size boat with 3.0 I ran a 19” 3 blade or 18” 4 blade for general use. Water skiing stepped down to a 16” 4 blade. Got similar speed and rom numbers with the 19/18 “ props, ski prop could over rev

like jimbo said look for nimbers on prop hub outside or near the prop nut that will give you a base line
 

Sea Rider

Supreme Mariner
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Sep 20, 2008
Messages
12,345
Motor could be running at high rpm but don't know if motor is over revving or not as haven't posted the max rpm achieved when water tested as loaded.. Need to know by how much is over revving from max 4800 wot revs, does the rev limiter if having one kicks in decreasing the rpm down ?

Happy Boating
 

rm2508j

Cadet
Joined
Jun 7, 2017
Messages
27
The current prop is in good shape, no nicks, dings or bent blades. I will look a the hub for numbers on the current prop. The motor has no rev limiter, it will over rev 150 to 200 rpm at full bore with 2 souls on board. I can only pull a skier with 3 total onboard and those 2 have sit up in the bow or I will never get on plane. I understand it’s only 140 horse and definitely not a powerhouse. The engine and drive are fresh. I rebuilt the engine last winter and replaced the outdrive the year before that.
 

TunaFish389

Petty Officer 2nd Class
Joined
Apr 26, 2018
Messages
184
If pulling skier to plan is problem.. Take current pitch and add a blade.. Ie three to four.. Should drop you 200 rpms too
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
So the motor is over revving + 150-200 revs towards max 5K with 2 up. A skier is the killer wave, adds to much water drag to the equation, So it's a 3 man deck load + skier. With current prop much better would be to leave one of the bow boaters on terra firme, motor should respond fasterr to take the combo out of the hole which will benefit the skier.

Can't have a single top prop performer for dual sports, that's skiing and boating at same time, it's one or the other. Just for the record, go for a wot ski run with only 3 and post whatever max rpm was achieved on flat calm water cond.

Happy Boating
 

rm2508j

Cadet
Joined
Jun 7, 2017
Messages
27
I will do some experimenting with different loads on the boat and get back to you all with the results. Thanks for all the input! It is much appreciated
 
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