prop damage

1ThOFA87 · 30 July 2009, 14:09

Good day! I have a 14 ft SIB sportboat on which I've fitted an approximately 20 year old 25 hp 2 stroke Mercury. I was able to obtain the engine for $900 and its run pretty good over the 4 years that I've owned it. I had a local marine mechanic give it a once over and he took care of some corrosion problems on contacts, installed a new impeller and replaced a few other worn parts and I must say it's not given me any major problems considering what I paid for it.

It does however have a few minor chips on the prop and it's not particularly sharp. How "perfect" does the prop need to be? I don't even know if it's supposed to be sharp (I'm such a newbie). I'm wondering if the condition of the prop is costing me performance. I has no major dings and it's not warped but there are a few chips on it as if someone had beached it in a rocky area. From what I've read on this forum, I know it wouldn't be worth a SS upgrade on a 25hp but would it be worth replacing this prop? Is it possible to have it refurbished somehow? Any advice would be most appreciated.

doggypaddle · 30 July 2009, 14:15

if there is no major dings, or warps I wouldnt worry about it. The edges dont need to be sharp like a knife, just smooth, so if there is roughness on the edges just polish the edges with wet or dry paper or a smooth file.
best bet is find out what pitch it is and find one on ebay cheap as a spare.
or....if you dont have a tacho fitted see what wide open throttle rpm you are getting, you may have more to gain in terms of economy and performance by runing a different pitch?

can you post pictures of the damage?

grego · 30 July 2009, 19:26

yeah, it's probably not a big deal for a 25hp but post the pics if you can. a spare is a great idea too, and you might find one that does give you a bit of a lift.

good luck.

Poly · 01 August 2009, 08:34

You can get props "reconditioned" for about £40 GBP (so probably $70 USD? - although prices never translate properly!). A new prop for a 25HP will probably be 2x that (or 3x if you have just broken it and are need it right now!).

The cost of a repair generally seems to have nothing to do with the amount of damage. If you are new - there is a fairly good chance that you will add some more scratches/small dings to the prop in the next few months - so you might as well hold off and get them all fixed at the same time!

Serious damage will cause the prop to vibrate and can cause serious engine damage - presumably its not that bad as your mechanic would have pointed it out.

willk · 01 August 2009, 10:52

Quote:

Originally Posted by Polwart

If you are new - there is a fairly good chance that you will add some more scratches/small dings to the prop in the next few months - so you might as well hold off and get them all fixed at the same time!

I can vouch for that, doubly! If you fit a stainless prop you will still "ding" it, the prop will hold up better but the shock will be transferred to the motor instead - with possible sad results. A cheap sacrificial prop has it's advantages.

And I've seen some real pros and old salts rip a prop to bits!

1ThOFA87 · 02 August 2009, 12:12

All great advice! Thanks!!! I'll post pics soon as I can.