prop selection help

[egldvrbags]

I have a 1995 Bayliner 2050 LS w/ a 4.3L Merc. I need a new prop. The one on there (it was there when I bought it, I'm the 3rd owner) is:

#48 78124 A40 23P

I can find a replacement of this prop on the internet.

Question: Is this the correct prop for my boat??

I use my boat to pull skiers, tubers, wake boarders, etc. Don't really care about absolute high end speed, but a quick hole shot is nice.

Thanks!

 

[Silvertip]

Re: prop selection help

The 23P seems reasonable for the boat. Whether its the "best" prop for the boat is unknown becaue you have not told us how the existing prop performs. The prop is correct if the engine can run at or near its maximum recommended rpm with an average load at wide open throttle. Some props are more efficient than others even though the pitch may be the same.

 

[egldvrbags]

Re: prop selection help

The 23P seems reasonable for the boat. Whether its the "best" prop for the boat is unknown becaue you have not told us how the existing prop performs. The prop is correct if the engine can run at or near its maximum recommended rpm with an average load at wide open throttle. Some props are more efficient than others even though the pitch may be the same.

Thanks. According to the previous owner, this prop is the original. One of the 3 blades has a gouge on the tip (which I did on my first outing). It does run at the spec RPM at WOT. But, since I don't have past experience with this prop in "new" condition, I don't know if a different pitch would give me a better hole shot than I presently get. Just don't want to overrev the engine.

 

[Silvertip]

Re: prop selection help

I would think the gouge in the blade tip would cause the prop to lose some efficiency so it is probably reving a tad higher than the same identical prop in new condition. Note that I said "identical". That doesn't mean just swapping one 23P prop for another. Two 23P props, one from manufacturer "A" and another from manufacturer "B" will not likely perform identically. They will be close in most cases but one cannot use the term "identical performance" in those cases.

 

[egldvrbags]

Re: prop selection help

I would think the gouge in the blade tip would cause the prop to lose some efficiency so it is probably reving a tad higher than the same identical prop in new condition. Note that I said "identical". That doesn't mean just swapping one 23P prop for another. Two 23P props, one from manufacturer "A" and another from manufacturer "B" will not likely perform identically. They will be close in most cases but one cannot use the term "identical performance" in those cases.

Thanks!

I'll probably just order one w/ the same part # as the one I have and see how it performs.

 

[dcg9381]

Re: prop selection help

It does run at the spec RPM at WOT. But, since I don't have past experience with this prop in "new" condition, I don't know if a different pitch would give me a better hole shot than I presently get. Just don't want to overrev the engine.

A lower pitch prop will typically give you better "hole" shot. It will also allow over RPM in most cases. The ideal prop is designed to give you a target RPM range at WOT, usually pretty high up there for a V8. I'd *guess* on a 4.3L probably 4500-4700 rpm.

Dropping the pitch = more accel, less top end, and more RPM.

23P sounds like a lot of prop for that boat, but I don't know the prop diameter.

Find a local prop shop that might let you "try" before you buy - they can also work magic on damaged props.

 

[egldvrbags]

Re: prop selection help

A lower pitch prop will typically give you better "hole" shot. It will also allow over RPM in most cases. The ideal prop is designed to give you a target RPM range at WOT, usually pretty high up there for a V8. I'd *guess* on a 4.3L probably 4500-4700 rpm.

Dropping the pitch = more accel, less top end, and more RPM.

23P sounds like a lot of prop for that boat, but I don't know the prop diameter.

Find a local prop shop that might let you "try" before you buy - they can also work magic on damaged props.

It's a 13.5 diameter. A local shop suggested going to 21P. Unfortunately, they don't have a "try" option. I'd love more acceleration, but don't want to over rev the engine.

Thoughts?

 

[Silvertip]

Re: prop selection help

You won't over-rev the engine if you watch the tach and throttle back when it begins to head into re-line territory. That's what a throttle is for. If you tow a lot of water toys the 21P would help get things moving. If that's what you do most it makes sense. But when you are in a hurry to get somewhere, make sure you watch the tach. Many of us have two props -- one for power and one for speed/cruising. The prop is the transmission for your boat and it has only one gear unlike your car. Therefore whatever you choose must be compromise between power and top end. You can't have it behave like a tow truck and a sports car with one prop.

 

[Silvertip]

Re: prop selection help

You won't over-rev the engine if you watch the tach and throttle back when it begins to head into re-line territory. That's what a throttle is for. If you tow a lot of water toys the 21P would help get things moving. If that's what you do most it makes sense. But when you are in a hurry to get somewhere, make sure you watch the tach. Many of us have two props -- one for power and one for speed/cruising. The prop is the transmission for your boat and it has only one gear unlike your car. Therefore whatever you choose must be compromise between power and top end. You can't have it behave like a tow truck and a sports car with one prop.

 

[egldvrbags]

Re: prop selection help

You won't over-rev the engine if you watch the tach and throttle back when it begins to head into re-line territory. That's what a throttle is for.

Agreed. I know how to do this but does my wife?????

If you tow a lot of water toys the 21P would help get things moving. If that's what you do most it makes sense.

Yeah, this is mostly what I do. I think I'll try the 21P and have the shop repair my 23P so I'll have both.

I really appreciate all the great advice.

 

[John_S]

Re: prop selection help

Does your '95 have Thunderbolt V ignition? It is near the transition year, If it does, it has a rev limiter and would be "wife" safe.

From the Bayliner parts manual:
4.3LX ALPHA I
ENGINE SYSTEMS
* 52258 175 HP MOD. 205 MERC SD TP PT EA 1
* 51144 13 1/2 X 23 PROP-MERC I/O EA 1

The 13" diameter is usually more of an outboard prop. The 14" diameter is usual for I/O runabouts. ???

How bad is the ding? Post a pic if you can. If its minor, it might be better to get some wot readings along with how well it pulls for water toys, before buying.

A stock type prop 14.25 x 21 x 3 should be a decent replacement, given the current is performing as said. It would give you more bite and pull, but will loose a little off top-speed.

 

[BAYLINER185]

Re: prop selection help

You could also try going Stainless

I have that same stock Prop so if you want it Ill sell it to you cheep. I only used it 3 X then went to Stainless so I dont need it and it wont work, well I havent tried it actually on my 28 foot cruser...HMMMM??? I have a 21 on the cruser now I could try the 23 and see what happens, I doubt I will like what it does on there though..........

Any way I went to a Stainless on my 07 185 that has the same motor as your boat. I kept the same #'s from the stock prop and went with the Stilleto with the same specs and the boat's whold shot is incredible and gained in overall top speed by almost 10 MPH.....Will not over rev as its WOT is right at 4200...

Just another option.

 

[egldvrbags]

Re: prop selection help

Does your '95 have Thunderbolt V ignition? It is near the transition year, If it does, it has a rev limiter and would be "wife" safe.

From the Bayliner parts manual:
4.3LX ALPHA I
ENGINE SYSTEMS
* 52258 175 HP MOD. 205 MERC SD TP PT EA 1
* 51144 13 1/2 X 23 PROP-MERC I/O EA 1

The 13" diameter is usually more of an outboard prop. The 14" diameter is usual for I/O runabouts. ???

How bad is the ding? Post a pic if you can. If its minor, it might be better to get some wot readings along with how well it pulls for water toys, before buying.

A stock type prop 14.25 x 21 x 3 should be a decent replacement, given the current is performing as said. It would give you more bite and pull, but will loose a little off top-speed.

Thanks for the info!

The boat is stored for the winter (awaiting our 2 weeks of summer in WI!!!!) so I don't have any pix. The ding is more of a gouge. I hit a rock in some shallow water in a no-wake zone.

My kids are small so getting out of the water on skiis is no problem. But, I think for an adult I could do a better hole shot (engine is tuned up, etc). So, I may go for a 21P and see the difference. I really don't care about top end.

 

[egldvrbags]

Re: prop selection help

Does your '95 have Thunderbolt V ignition? It is near the transition year, If it does, it has a rev limiter and would be "wife" safe.

Not sure about the ignition.

I'm a mechanics dream. I have a trusted mechanic that takes care of everything for me, winter/summerization, etc. I grew up working on cars, but just don't have the time (too many irons in the fire) to work on the boat - I leave it up to the professionals.

Anyhow, when I get the boat out of storage, I'll check the ignition.

The engine SN is 0F436164

Thanks!!

 

[egldvrbags]

Re: prop selection help

You could also try going Stainless

I have that same stock Prop so if you want it Ill sell it to you cheep. I only used it 3 X then went to Stainless so I dont need it and it wont work, well I havent tried it actually on my 28 foot cruser...HMMMM??? I have a 21 on the cruser now I could try the 23 and see what happens, I doubt I will like what it does on there though..........

Any way I went to a Stainless on my 07 185 that has the same motor as your boat. I kept the same #'s from the stock prop and went with the Stilleto with the same specs and the boat's whold shot is incredible and gained in overall top speed by almost 10 MPH.....Will not over rev as its WOT is right at 4200...

Just another option.

So what pitch prop do you have on your 185?