Bayliner Ciera prop question

[Alex57]

Hi Everyone,

I have a 1996 Bayliner Ciera 2355

I got a dent in the prop so I will be changing it before she goes back into the water (as soon as the snow is over that is)

She's got a 5.7 Mercuiser 2bbl with an alpha 1
She planes well and cruises around 20mph at 3300rpm, but top speed is only about 30mph at wot 4200rpm.

I am wondering if I got the right prop on there (unfortunately I have no idea what kind it is, or which one it should be by factory specs).


ANy suggestions on what prop it should have? Is 4200rpm and 30mph as good as it's going to get or can I get a little more out of her with a different prop?

What kind?

Thanks.

Alex.

 

[Bondo]

Re: Bayliner Ciera prop question

Hi Alex,......

Same answer applies down here as I just left for you up in the I/O forum,........

Without Knowing What prop you have on it Now,.....

Makes a Good Answer about Impossible........

 

[Alex57]

Re: Bayliner Ciera prop question

Hey Bond-o

Thanks for your reply.

is thre any way to find out what prop I have? measure it somehow? or do they have serial numbers of some sort?

Otherwise, I suppose a good answer is impossible unless someone has the same boat with the same motor and outdrive, in which case, they would know what kind of performance to expect and wht kind of a prop came factory.

 

[Silvertip]

Re: Bayliner Ciera prop question

Look at the prop hub. It will have either a part number or numbers such as 15 x 19. 15 = diameter, 19 = pitch. There is no "factory spec prop" although on I/Os they can get fairly close. You install a prop that allows the engine to rev at its maximum recommended RPM at wide open throttle. Whatever speed that provides is what you get. There isn't much other "tuneability" on an I/O other than adding trim tabs or Smart Tabs and playing with prop designs (all props of the same diameter and pitch are not equal in efficiency).

 

[Alex57]

Re: Bayliner Ciera prop question

Thanks Silver,

I do have trim tabs and the motor runs good (for a 2bbl), so i was just wondering if 30mph makes sense at 4200prm WOT.

I guess if its not the speed, but the rpms you look at, and the rpms should be 4400-4800.. then I do have the wrong prop.

Now the question is, will going down 1 or 2 sizes (in pitch), raise the rpm to the 4600 rpm range and if so, am I actually going to go slower as far as top speed?

 

[Alex57]

Re: Bayliner Ciera prop question

Ok for everyone that gave input, I found out whats on there.

It was a 15X15 3 blade aluminum prop.

So my options are either:

1) To replace with the same size prop and try to figure out why it won't rev past 4200 rpm. ( I suspect it is the mercarb)

or

2) To get a 14Xsomething (14 pitch) prop which will bring the rpms up, but which will most likely not give me any more top speed.

I don't want a SS prop becasue in my experiance, and from what I have heard, it is better to damage and replace the aluminum prop than to run into somethign hard which will not damage the prop but instead possibly damage the outdrive (as the schock transfers).

I guess teh real question now is can the carb (which i will be rebuilding) be the problem and cost me a few hundred rpms?

and if not what else could be the issue?

 

[tommays]

Re: Bayliner Ciera prop question

You can check with BOC(bayliner owners club) forum BUT i think a healthy motor should be able to push that prop unless the boat is just got a lot of stuff in it


And you did mention a ding ? i have seen a lot of dings here that peolple thought were minor and hafe the prop was missing ?


Tommays

 

[sabastianunf]

Re: Bayliner Ciera prop question

I would get the boat tuned properly - rebuild carb, replace plugs, check old ones for things like rust and carbon build-up and gap the new ones per specs, replace wiers, check distributor, compresion and timing before buying a prop. If you have alot of hours on the motor you may want to clean with seafoam. If it still doesn't hit your range at WOT then go with a smaller pitch on the prop. for example going from a 15 to a 13 pitch will probably raise your rpm @ 400. I went from a 19 to a 17 pitch on my boat and it gets a whole lot better hole shot and did not loose much at all on my top end. You are right - If you plan on hittling alot of stuff stick with aluminum especially if you are not sure you have the right pitch. Also my merc has rec rpm range listed on the valve cover- find out what they recomend for your motor.

 

[sabastianunf]

Re: Bayliner Ciera prop question

Just realized you have a 5.7 L and 15" x 15 pitch prop? I am running a 1977 2.5 L 120 hp merc sterndrive on a 19 foot cuddy cabin and it pushes a 15 x 17 pitch very well - Either your prop is not a 15 pitch or your motor is not running well at all.

 

[Alex57]

Re: Bayliner Ciera prop question

Or the boat is just bigger and heavier...

 

[Bondo]

Re: Bayliner Ciera prop question

Your 15X15 prop is already at the Bottom of the Normally available range of Pitches,.....
Most replacement aluminun props are normally available from 15" to 23" of pitch......
Atleast the 1s that'll Fit your Mercruiser Drive....

Unless you can find a Problem with the Motor, or the Hull,.....
You're looking at Regearing your drive to the Next Lower Gear Set......

 

[Alex57]

Re: Bayliner Ciera prop question

Thanks Bondo,

I will leave the 15 x 15 on there, check the timing, rebuild the carn and check the linkage (for opening all the way) and post back.

i appreciate the advice, us newbies have it rough...

 

[sabastianunf]

Re: Bayliner Ciera prop question

be sure to check your plugs and compression - they can tell you alot.