WOT of 5100. Manu. says 4400-4800 What to do?

[doublehelix]

I have a 18.5 ft. Bayliner with a 3.0 engine with a 14.25 inch, 21 pitch aluminum prop. At WOT I am running at 5100 RPM at around 42 MPH (via GPS reading). The manufacturer suggests WOT be between 4400 and 4800. Does it sound like I need to go to a 23 pitch prop or should I just switch to the same size stainless steel prop? # blades or 4? Mostly I use the boat for tubing or just running up and down the river/lake.

Thanks for any suggestions you might have.

 

[thelightning]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

A fourblade would be nice for skiing/tubing and stuffs, smaller pitch is good for a fast holeshot but for topend you would take the 23pitch

Just try and borrow a prop first to see how your boat reacts with it because you might have a sucky holeshot with a 23pitch or u might even lose topend.. 5100 isnt that bad if you may run max 4800.

 

[Dhadley]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

What brand outdrive?

 

[doublehelix]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

Alpha 1 Gen 2. Year 2000.

Doesn't seem to be many/any 14"x23 pitch 4 blade aluminum props out there. Anyone have a part number for such a beast?

Thx.

 

[jpg1130]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

Tach may be incorrect....

 

[playyas4u]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

I think your tach may be wrong or either your prop is damaged and slipping. I have a OMC 3.0 and is considering going to a 21 pitch but thought it may be too much for the motor. Just my 2 cents.

 

[John_S]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

Yep, check the tach, but even if accurate, I wouldn't be that concerned. Just bring the rpms down a little. I have always found I like to be slightly underproped, ie able to hit the high range of spec or slightly over. I prefer the better holeshot, and if you do allot of stop n go, especially water sports or fishing, I think you will to.

 

[StangLX302]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

I have the exact same problem. Just to save you some trouble and time. I tried a Black Max 14 x 23 on my Bayliner 175 with a 3.0 engine. The holeshot was really bad and I lost 3 mph. My factory prop was exactly the same size as yours. I'm experimenting with Turning Point Hustler props right now and I'll let you know how it works out once I get the perfect one.

For now, just throttle back a bit when it winds out like that. You don't want to run your engine at that RPM for long. I can't see it hurting if you just do it for 30 seconds or so.

 

[doublehelix]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

Hmmmm. Thanks for all the replies. I do have a rather significant chunk missing from one of my blades so perhaps it is slipping a bit. If the hole shot sucked with a 14x23 wouldn't a 4 blade 14x23 make up for that? Better bite with 4 blades? I think I am going to try a 4 blade 14x23 and see what happens.

I'll post the results after testing.

 

[John_S]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

In aluminum, the four blade props are generally on even pitch numbers. Common up to 20" pitch. I think 22" and larger will be hard to find, or limited selection. The general rule for 4 blade is to drop the pitch by one inch compared to a 3 blade. Better hole shot, but some loss of top end.

 

[tommays]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

Your pretty much right were you want to be


With 12 years of 3.0 time i can tell you anything bigger is going to make the boat a DOG.

There is just NOT enough HP at low RPM in a 3.0 motor to spin more prop unless you want to run around buy yourself with 8 gallons of gas in the tank and through all your stuff overboard



Tommays

 

[Outsider]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

I do have a rather significant chunk missing from one of my blades so perhaps it is slipping a bit.

Ahhh, the rest of the story. Run it that way long and a prop will be the least of your worrys ...

 

[StangLX302]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

Hmmmm. Thanks for all the replies. I do have a rather significant chunk missing from one of my blades so perhaps it is slipping a bit. If the hole shot sucked with a 14x23 wouldn't a 4 blade 14x23 make up for that? Better bite with 4 blades? I think I am going to try a 4 blade 14x23 and see what happens.

I'll post the results after testing.

I still think that's too much prop. I would think a 4 blade 14 dia x 20 pitch would work better.

There's a thread on http://www.baylinerownersclub.org/forum/ titled Pinging 175/185 3.0L owners only please... Check that one out. A member by the name of Quakindude just bought a 4 blade 14 dia x 20 pitch and is going to try it out this week.

 

[BAYLINER185]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

I have a BRAND new 07 BAYLINER 185 and it came with a 14 1/2 X 23 pitch prop.

Im easily hitting 5K RPM and only getting a top speed of maby 35 MPH.

I have the 4.3 190 Hp motor.

I talked to my dealer today about this and they think the prop is too small w/ too much pitch and I am bringing in the boat for them to swap to a lower pitch tomarrow for more trials.

I had a 3.0 engine in a webcraft 19 footer 10 years ago and I think it had a 16" X 14 pitch and that boat did 45 mph and was pretty fast for how heavy it was for that little 4 banger motor.

This BAYLINER should be just about as fast with a lot less effort, right now its not. Ill let you know what My dealer works out for me and what I feel the change is. I think once we figure out the prop size I will buy the same specs in a SS model

Vic

 

[Dhadley]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

Lower pitch will yield more rpm and less top end.

 

[BAYLINER185]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

I just talked to a prop dealer that is highly recomended here in town and he tells me Im over proped. ( 14 3/4 X 23 pitch )

He says I should go to a 21" Pitch so I just bought a new 15 3/8" X 21" Prop here on IBOATS. ( slightly bigger diamater too )

He tells me a lot of these new boats come with my stock prop since mercruser gets a good deal on them and they "work" with the boat maby just not how I would expect it to.

doublehelix
I have a BRAND NEW used it for 5 hours on SUNDAY off my 07 BAYLINER 185 prop if you want to buy it cheep.

Its a 14 3/4 X 23 Pitch. Ill sell it to you for 1/2 what I just bought the new 21 for if thats cool? Email me at vraudio@msn.com

Again the prop is brand new no nicks of any kind and if I get this new 21p by the weekend I really wont need the 23p as it seems to be too much pitch and have been told to go down in pitch.

If it turns out Im wrong then I have to start all over agin but I will already know the 23Pitch is still not going to work for me. At that point Ill let the dealer play with it.

 

[BAYLINER185]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

Lower pitch will yield more rpm and less top end.

If what your saying is true I will soon find out wont I..............I hope not.....since I have no top end as it is and doublehelix is at least getting up to 42 MPH on a 3.0 I think Ill at least get my 45 MPH on the 4.3 with a 21p prop.


So knowing where Im at DHADLEY what do you recomend? I havent gotten any good answers from any one around here ( my neighborhood )

 

[John_S]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

Bay185, unless you have an odd drive ratio for a V6, your 23" pitch prop must be slipping or tach is wrong. A 185 with V6 should be doing high 40's, low 50's with light load. I've even seen some reporting mid to high 50's.

I am not sure why the shop recommended the 15" dia prop. Small runabouts are usually better with 14" prop series.

 

[BAYLINER185]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

IMPORTED JOHN S

Well I assume the prop is slipping but theres nothing I can do about that.

Im hoping the boat can do high 40's close to 50. The prop shop said to go to 21 pitch I decided to go with the 15" prop on my own really. I figure a bigger diamater will push more water and be me effeciant and then compensate for dropping pitch. I hope Im right.

I dont understant why if Im supposed to have a 23 pict why Im getting no speed out of this new boat. They made a tach adjustment but I doubt its going to anything for speed.

The only other thing I can think is the problem is the drive is not trimming up or down enough?

Is there any way to set the stop on the TRIM so I can raise the bow more? I think there was a way I did it on my WEBCRAFT 10 years ago but I totally dont remember.

can that be the problem Im not getting enough of the boat out of the water to get to correct plane? It really doesnt seem like thats the problem though becasue the boat does get on plane, at least it seems to.

OH PS the drive ratio is 1:81

I figure thats AWESOME since the prop will spinn 81 X to one crank shaft turn. Sounds pretty fast to me. Maby thats too fast for a 23p?

 

[chaparral442]

Re: WOT of 5100. Manu. says 4400-4800 What to do?

If your bow is plowing you need Smart Tabs- On a short I/O you may have a disproportiate amount of weight in the stern particularly if the gas tank is located in the stern.

Tabs will lift the stern out of the hole and push the bow down

Best $120 you will ever spend. They will also provide stability in turns and reduce porpoising