View Full Version : Same Prop Different Performance

06-27-2010, 10:30 AM
On my 2005 245 with MCX, the OEM prop was a 13.7x17.5. It was OK on the bottom end and provided a good cruising speed of 46 mph at 5100 rpm or so. I just put a new prop with the same specs on the boat and the hole shot is great but the speed is 41 mph at 5400 rpm, I thought these engines had a rev limiter. It also seems to slip quite a bit more than the old prop.

Any thoughts on the what could be causing these differences?

What about the rpm issue?

06-27-2010, 10:33 AM
One thing that comes to my mind is the cup. Do you know what the cup is on both props?

06-27-2010, 10:41 AM
I just checked and the pitch on both props is 17" not 17.5".

Cup? The original prop is stamped "130 B". The new prop is not marked.

06-27-2010, 11:06 AM
I would agree with the cup. I managed to take out my prop a couple of years ago, bought the same spec prop ended up with less top end and hit the rev limiter. So I can tell you from experience that my PS197 does have a limiter. Eric at OJ checked the prop and found that the previous owner must have taken most or all of the cup out of the prop and were able to put it back to its spec. Speed came back and I was no longer hitting the rev limits. I can say nothing but good things about Eric at OJ!

06-27-2010, 11:30 AM
So the old prop stamped "130 B" may have more cup that the one not stamped? Would the 130 mean .130" of cup? I cannot visually check the old one to see if there is a difference in them. See excuse attached.

Does anyone know what the standard cup on this size OJ prop would be?

06-27-2010, 02:00 PM
Is that what's left of your old prop? I think we deserve to be told the story.

The OJ Props (http://ojprops.com/products/revolution) page (Click on the "chart of available propeller sizes" (http://ojprops.com/resources/props.pdf) to get the list of sizes they currently offer) doesn't show a 13.7 x 17 HC prop (Perhaps HC means "High Cup"?). Hopefully Eric will be by to give a more authoritative answer...


06-27-2010, 05:14 PM
DANG! All 4 flukes are gone off that wheel!!!!!!!!

06-27-2010, 06:19 PM

06-27-2010, 07:46 PM
Canyon Lake Texas public ramp 7. The water level last year had dropped so much that this was the only ramp open. The concrete ramp ended about 6 feet from the waters edge so the trailer just kind of falls off to a 30 degree angle. You cannot stop before the drop off because the nose wheel on the trailer would be a foot too high to catch the nose of the boat. So you sink the trailer and hope. Well this time the trailer was so deep that the vertical padded guide bumpers actually floated off while I was trying to load. The boat moved sideways, missing the nose wheel, and the prop hit the wooden sliders and then the steel trailer itself. It chipped the paint on the trailer.

But hey, this bronze piece acted as a mechanical fuse and saved the prop shaft and transmission from any damage.

It was actually kind of funny when people said "Why don't you go pick up the blades and put them back on.". I had the tell them they were not supposed to come off....

06-27-2010, 10:18 PM
OK. I've been on this board for a few years, and that's the worst prop I've ever seen. The story's good, but it looked it would be better.

Look for Eric tomorrow; he should have an answer for you.


06-27-2010, 10:21 PM
I agree agree about talking with Eric from OJ props.

06-28-2010, 02:30 AM
OK. I've been on this board for a few years, and that's the worst prop I've ever seen. The story's good, but it looked it would be better.

Look for Eric tomorrow; he should have an answer for you.


Well Frank, I ain't been on this forum long, but I been around boats forever. As a matter of fact, I spent my 9th - 12th months of my lil life on our 1st shrimp boat the Gilbert and I'm gunna have to go with you on this one. I too ain't NEVER EVER seen a wheel come apart like that! I've seen 1 fluke broke off yeah, and bent to h*** from running over oyster reefs.

Man! Another GREAT reason to NOT have a stainless wheel... :cool:

07-02-2010, 02:15 PM
Hey Stout -
Did you ever get any useful info on this? If not, PM Eric (http://www.mastercraft.com/teamtalk/member.php?u=1537).

07-02-2010, 02:52 PM
I have the same OJ Prop (13.7 X17). I noticed a very small ding on one blade but the boat ran fine, so I sent the prop to a repair shop that I had used in the past. They charged me 3/4 the cost of a new prop and it looked like crap when I got it back. They sent me all kinds of charts and graphs on the prop but I lost 2 MPH off my top end. I talked with the guys at OJ and they told me to ALWAYS send the prop back to them because most repair shops can't get the props back to specs and it will be cheaper also. The prop looks normal from the rear, but it looks like they used a small air hammer on the leading side of the blade. Two 13.7 X 17 props made by two different manufacturers will not perform the same.

I thought the dimples on that one blade would make it go faster, or should I put wax on it?:rolleyes: