over-reving omc 3.0 bayline capri 1950

[wcasey5]

I bought the boat this year, it is a 1988 bayliner capri cuddy, 3.0 omc. It came with 2 props, a 4 blade and a 3 blade. I tried both, although the 3 blade is really beat up, the engine will rev to 5K or more If I hit WOT. The 4 blade is a 13.25 X 14 and the 3 blade is a 13.25 X 15. The holeshot feels really good, but I would like a bit more top end for cruising and keep the rpm's down. Currently I am maxing out at 36mph on the gps. I am happy with the speed, but would like lower rpm, down in the 4K to 4600 range WOT.

If I am going to a new prop, should I try a 17 pitch, or go right for the 19 pitch? 4 blade or 3 blade? Thanks

 

[Bondo]

Re: over-reving omc 3.0 bayline capri 1950

If I am going to a new prop, should I try a 17 pitch, or go right for the 19 pitch? 4 blade or 3 blade?

Ayuh,... I think the 19" will probably be Too Big,...

Luggin' the motor, burns Holes in pistons,.... Ya wanta be Able to pull 44/ 4600 rpms at Wot....

 

[QC]

Re: over-reving omc 3.0 bayline capri 1950

Just to be sure, will it pull past 4600 easily as is? I agree with Bondo, but we should really know how high it will go as is. Of course you don't want to overspeed, so I think we should know how easily it seems to hit 4600. If you have to do a lot of trimming and playing to get her to 4600, then even a 17 could be too high. All of this assumes the tach is right.

 

[steelespike]

Re: over-reving omc 3.0 bayline capri 1950

Something just doesn't add up.Calculations indicate 5100 rpm with a 1.86 ratio and 10% slip= 32 mph.
At 6% 34 mph. I figured this early today maybe I messed up.
This seems to indicate it could be turning even more than it says.Maybe I got the wrong ratio
Or it was timed down stream in a strong current.

 

[wcasey5]

Re: over-reving omc 3.0 bayline capri 1950

It gets to 5000 very easy. I don't have to trim, play around, nothing. Just gun the throttle and bang I'm there. This is using the stock tach, but it does sound like it is revving that high.

 

[QC]

Re: over-reving omc 3.0 bayline capri 1950

I'm with spike. I think the tach is off. I'm seeing 5357 RPM at 36 MPH and 12% slip. I think that's pretty reasonable.

 

[wcasey5]

Re: over-reving omc 3.0 bayline capri 1950

I'm with spike. I think the tach is off. I'm seeing 5357 RPM at 36 MPH and 12% slip. I think that's pretty reasonable.

It was reading over 5000, so this is in the ballpark. And the GPS hit 36 very briefly.

 

[QC]

Re: over-reving omc 3.0 bayline capri 1950

OK then. You'll lose some hole shot for sure, but if the tach is right, it sounds like a 19 may be in order. I think I'd still want to verify the tach, but the numbers do add up.

 

[wcasey5]

Re: over-reving omc 3.0 bayline capri 1950

Thanks. I'll try to get a verification on the tach. Thanks for the help, I really appreciate it.

 

[palace]

Re: over-reving omc 3.0 bayline capri 1950

I have 1987 19' capri 3.0 open bow. stock prop was 13 3/4 X 15 4800 RPM/WOT. Tried Hustler 13 1/4 X 17 and Solas 13 1/4 X17 get better hole shot 35 MPH, 4600 RPM/WOT. Hustler is my backup as it does not have as good of a hole shot or cornering. I was in local prop shop last year and spoke with a Rep. and she said they had tried the same prop on two of the same boats (exact same set-up) and they performed completely different. Try and get close where you want and try different brands. Right now I am sold on Solas for my Aluminum. Good Luck. If you have a Cobra shop manual there is a prop page that can help you narrow which prop will work best.

I bought the boat this year, it is a 1988 bayliner capri cuddy, 3.0 omc. It came with 2 props, a 4 blade and a 3 blade. I tried both, although the 3 blade is really beat up, the engine will rev to 5K or more If I hit WOT. The 4 blade is a 13.25 X 14 and the 3 blade is a 13.25 X 15. The holeshot feels really good, but I would like a bit more top end for cruising and keep the rpm's down. Currently I am maxing out at 36mph on the gps. I am happy with the speed, but would like lower rpm, down in the 4K to 4600 range WOT.

If I am going to a new prop, should I try a 17 pitch, or go right for the 19 pitch? 4 blade or 3 blade? Thanks

 

[wcasey5]

Re: over-reving omc 3.0 bayline capri 1950

I have 1987 19' capri 3.0 open bow. stock prop was 13 3/4 X 15 4800 RPM/WOT. Tried Hustler 13 1/4 X 17 and Solas 13 1/4 X17 get better hole shot 35 MPH, 4600 RPM/WOT. Hustler is my backup as it does not have as good of a hole shot or cornering. I was in local prop shop last year and spoke with a Rep. and she said they had tried the same prop on two of the same boats (exact same set-up) and they performed completely different. Try and get close where you want and try different brands. Right now I am sold on Solas for my Aluminum. Good Luck. If you have a Cobra shop manual there is a prop page that can help you narrow which prop will work best.

Sounds like good advice. I think i'll start with the 17. I'll look up Solas. I want to sneak up on this and not buy something that is useless. Thanks

 

[mark1905]

Re: over-reving omc 3.0 bayline capri 1950

Remember though that he has a cuddy vs an open bow which is going to be adding some serious weight. A 3 blade 13.5-14 x 17p does sound about the max.

On my light little 7' 1" transom 18' BR, my 14" x 19p can over rev with just me or my 100lb girlfriend in it.. but add a few friends, and it's perfect. I wouldn't want anymore pitch.

My thought on props is that you need to look at the overall situation instead of how it's performing with just you in the boat and adjust accordingly.

 

[MBAKER]

Re: over-reving omc 3.0 bayline capri 1950

We had the exact same boat in an '87 vintage, and we ran a 15P 3 blade on it. It would over rev if you didnt throttle it back on the top end, but it did pull from a stop pretty good, surprisingly good actually for a 3.0. So we never messed with it, always wanted to try a 4 blade 15 or a 17 but never did. Rarely ever able to run wide open anyway so a little more speed doenst matter to us, and its not a big deal to watch the tach and throttle back as needed to keep from over revving. Plus I woudl rather have a good hole shot and not work the motor so hard when we add more people. I know just cruising it will be running a few more rpms but it didnt lug the engine as hard so I dont know that there would be much effect on fuel use either.

 

[wcasey5]

Re: over-reving omc 3.0 bayline capri 1950

excellent advice, thanks