May have damaged prop, recommendation for replacement?

[Cheekzilla]

Was putting my boat on the trailer this weekend and I think I knicked it on the boat ramp when trying to get it all the way on. See photos below.

I'd like to get a replacement that allows the driver to hold lower planing speeds when pulling a wakeboarder, not really concerned about top speed because I don't really push it above 3500-4000 rpm which is normally cruising between 30-40 mph depending on load. Here's my info:

1. Performance problem - may have damaged prop, want one that will allow lower planing speeds below 20mph, not concerned about loss of top end
2-3. Current prop - stock Volvo penta stainless 3 blade 14.75" x 19p (part no 3860708)
4. WOT rpm - not really sure, volvo says its 4800 rpm, not sure of speed because I don't push it that hard
5. Engine - 2002 VP GL-B 5.0 2bbl carb 220 hp
6. Boat - 2002 Four Winns Horizon 200 20' ~3900-4000lbs

Here's what my current prop looks like (sorry if photos don't work at first)

https://www.dropbox.com/s/nfkwcuewstpij49/IMAG0814.jpg
https://www.dropbox.com/s/bdq1yvgnp4hpgwo/IMAG0815.jpg

 

[Bob_VT]

Re: May have damaged prop, recommendation for replacement?

Unless you put a big bend in a blade that prop will still work fine. That is minute damage at best.

 

[Cheekzilla]

Re: May have damaged prop, recommendation for replacement?

Unless you put a big bend in a blade that prop will still work fine. That is minute damage at best.

Ok cool. Still don't know if I spun it when it hit. My motor cut off automatically so hopefully that prevented damage to the shaft and bearing

 

[alorio1]

Re: May have damaged prop, recommendation for replacement?

I don't think you have to worry about shaft or bearing, I hit a large chunk of cement while pulling into a boat launch and my prop looked like a twisted pretzel, bottom part of skag broke but shaft and brgs were ok. I think you will be just fine, just like Bob_VT said.....

 

[Cheekzilla]

Re: May have damaged prop, recommendation for replacement?

I don't think you have to worry about shaft or bearing, I hit a large chunk of cement while pulling into a boat launch and my prop looked like a twisted pretzel, bottom part of skag broke but shaft and brgs were ok. I think you will be just fine, just like Bob_VT said.....

Sounds good. Even if it's fine, can someone answer my query about an upgrade for the performance I was looking for? It's kind of overwhelming to me trying to determine pitch and blade count and also manufacturer.

 

[QC]

Re: May have damaged prop, recommendation for replacement?

I would consider a 4 blade 18 inch pitch. Use the slightly, if at all, damaged prop as a spare which you need anyway. You can clean up small micks with a file, and repair even small bends with a hammer, and some sort of anvil. Two hammers work even. Go sloooowwwww.

 

[jestor68]

Re: May have damaged prop, recommendation for replacement?

Need a full throttle run with rpm and speed to determine what pitch to recommend.

You can't determine if a prop is correct without running it wide open to see if it operates within it's recommended rpm range of 4400-4800 rpm.

I checked the prop selector and it said a 17 pitch(with an operating weight of 3699), but that's just an estimate. The only way to select a prop is through on the water testing.

The selector indicated that with a 15 X 17 pitch, with your 1.51 gear ratio, you might see 4700 rpm @ 46 mph. But we'll have to wait and see what that 19 pitch prop does before making a move.

 

[Cheekzilla]

Re: May have damaged prop, recommendation for replacement?

Need a full throttle run with rpm and speed to determine what pitch to recommend.

You can't determine if a prop is correct without running it wide open to see if it operates within it's recommended rpm range of 4400-4800 rpm.

I checked the prop selector and it said a 17 pitch(with an operating weight of 3699), but that's just an estimate. The only way to select a prop is through on the water testing.

The selector indicated that with a 15 X 17 pitch, with your 1.51 gear ratio, you might see 4700 rpm @ 46 mph. But we'll have to wait and see what that 19 pitch prop does before making a move.

I see now why you need to know that since a different pitch and/or diameter will increase/decrease RPMs. I'll try and do some testing soon. BTW, I forgot to mention it, but my outdrive says the gear ratio is 1.6:1

 

[Cheekzilla]

Re: May have damaged prop, recommendation for replacement?

Did a full throttle run yesterday with 8 people on the boat, plus a cooler, so we'll call it 1400-1600 lbs. Full throttle, drive trimmed to the top of the range, 4250RPM, about 42mph (according to speedo, dunno how accurate). Manual says operating range is 4400-4800 rpm. Thoughts?

Edit: also had a full 30 gallons of fuel

 

[Cheekzilla]

Re: May have damaged prop, recommendation for replacement?

What about these two? Both 18 pitch and 4 blade stainless, stiletto is 14" diameter and the Michigan wheel is 14.37"

Michigan wheel Apollo

Stiletto Bay Pro II