Does a dinged up prop really perform this bad?

[kwerdal]

Hi everyone I am fairly new to the boating world I have a 1989 Gemini Bass boat 200DCX with a Raker 14.25 x 26 p (20 foor with a 89 Johnson 200GT) when i got the boat the prop only had a few nicks and would run 54 mph on the speedo tack was broken. I messed up and got into the bottom a week later and the are some large nicks but no chunks missing the boat would only run 45 at 5900 WOT after that does it really make that big a difference? the RPM almost seem higher then before the damage but I cannot prove that.

I bought a Raker 14.25 x 20 to try but after doing some reading this may raise my RPM higher then I want it I plan to test it easy so I don't hurt the motor.

Kevin

 

[crxess]

Re: Does a dinged up prop really perform this bad?

Sounds like you have a center hub starting to slip from the impact. Less speed but More RPM's
You really need a tach more than the speedo. helps to keep track of operating condition and troubleshoot things.

Send the prop to be rebuilt and use the 20p gingerly until it gets back. You can keep the 20p for a backup or replace it later with a higher pitch.

And while dings effect performance a bit, changes to the blade angles from impacts does a lot more.

 

[kwerdal]

Re: Does a dinged up prop really perform this bad?

Sounds like you have a center hub starting to slip from the impact. Less speed but More RPM's
You really need a tach more than the speedo. helps to keep track of operating condition and troubleshoot things.

Send the prop to be rebuilt and use the 20p gingerly until it gets back. You can keep the 20p for a backup or replace it later with a higher pitch.

And while dings effect performance a bit, changes to the blade angles from impacts does a lot more.

I didnt know the center hub could slip! that would make sense it would suddenly jump up in RPM (Tach is fixed now) but the boat felt like it nosed over.. I would just back off and run about 30 MPH I THINK the 26 p was running 5400 RPM at WOT but if I have read right the 6 degree pich change could add a lot of PRM the said 300 to 400 every 2 degrees is that right?

Oh and the boat is about 1450 lbs with out my 200 lbs butt in it accoring to the NADA guide

 

[steelespike]

Re: Does a dinged up prop really perform this bad?

Usually if a hub slips it loses it entirely. being unable to plane.The likely hood of slipping enough to just change the rpm a little is really unlikely.
More than likely the blades are messed up enough to disturb the performance.
Thats a pretty sofisticated prop I don't think it would take much to ruin its performance.
They can repair the prop and may be able to check for a spun hub.
Pitch is measured in inches. Yes your 20 will wind up too much.Could add
1200 rpm.

 

[cribber]

Re: Does a dinged up prop really perform this bad?

I banged up my prop last year and it definitely impacted performance. I hit a sandbar nicking it up and also bending the blades back ever so slightly changing the pitch causing my RPMs to go up and WOT speeds to drop.

 

[kwerdal]

Re: Does a dinged up prop really perform this bad?

I found a Turbo 14.25 x 24 for $110 shipped how would that perform as compared to the Raker 26 p?

 

[steelespike]

Re: Does a dinged up prop really perform this bad?

In my opinion you should get your old prop fixed and see how it performs.
Get the present max rpm and speed by gps.You presently don't know how it runs with a prop in excellent condition.
Someone may be able to compare those props and may even be able to guesstament how they might perform on your boat.
You might read the prop helps on the prop store page.

 

[Maclin]

Re: Does a dinged up prop really perform this bad?

Yes, it can make that much difference.

Case in point, a DuoProp I/O but same principle:

• Original 26 pitch (B7) props in bad shape, 42mph at 4600+rpm.
• Replaced with new 23 (B5) inch props, 48mph at 4400-4500 rpm.
• Replaced with new 26 (B7) inch props, 50+ at the same 4500rpm's, just took longer to get the top speed

Same time, same place same "boat" channel.

 

[kwerdal]

Re: Does a dinged up prop really perform this bad?

I do plan to repair this prop here is a pic you should be able to see more pics once you get to this one

http://rides.webshots.com/photo/2415263180067081283oMesQK?vhost=rides

 

[QC]

Re: Does a dinged up prop really perform this bad?

I went ahead and added that pic directly to your post. Yup, that thing pretty much sucks. That's not "dinged up", that's kinda big wiggles . . .

I agree with steelespike, get that one fixed and then get some good baseline numbers, then let's talk about what other stuff can be done for mo betta sumpin' or other. Better top speed, better hole shot, better yeehaws, whatever . . .

 

[WIMUSKY]

Re: Does a dinged up prop really perform this bad?

That's banged up pretty good. Plus it's going to be out of balance which is tough on everything.....

 

[kwerdal]

Re: Does a dinged up prop really perform this bad?

I have the new prop on it now but I havent had it out yet so i will not damage anything. I didnt realize how bad that was i guess. I am learning a lot the last few weeks. Thank you guys for all the info will let you know how the other prop does and get this one out for repair.

 

[crxess]

Re: Does a dinged up prop really perform this bad?

Always run a hand along the blades. If you feel nick and rough spots, it can usually be dressed and continue using. If a chunk is missing or it feels warped, it needs professional repair.

 

[hwsiii]

Re: Does a dinged up prop really perform this bad?

Kwerdal, Spike and QC are 100% right, you need to stay with the Raker 26" prop as it is designed for very high motor mounting and it will do muchhhh better than the 24" Turbo. The Turbo is an excellent prop but for your application the Raker is much better.


H