Broken Tip

[FORCE10]

I have a 13 3/4x 17" alum. Prop with 1/2" of one blade broken off.my question is:
Can i remove the same amount off the other two and reshape the tip.it seems possible altho it would reduce the diam. To somewhere in the neighborhood of 12.5? I realize the best thing to do is buy a new prop,which of course i plan on doing,but i haven't ran this boat and motor combination yet.(17' tahiti w/85hp)so i want to get a general idea of what prop size i need.
Curious as to if this is possible

thanks,force10

 

[Bifflefan]

Re: Broken Tip

sure you can do that, but as for "getting an idea", no, that is probably not going to help you unless your a pro prop repair guy.
Most prop shops repair them for about 60 bucks and a new one is about 120.
For the best info, get a new one the same as what was on it and go from there. 17 and 19p are the most popular.

If you get the balance off then you risk tearing up the lower unit. Thats not worth it.

 

[Frank Acampora]

Re: Broken Tip

Sure, it can be done. You just need to be careful. I set up a jig on my drill press to ensure the same amount is taken off each blade.

Understand that reducing the diameter will reduce the blade area and rpm will rise a bit--exact amount? Depends upon how much you remove and how you have reshaped the blades.

 

[RicMic]

Re: Broken Tip

Sure, you need to do something as its out of balance in weight and thrust. I would make a template out something so that I could get all the blades the same and it really should have the balance checked. The other side of the coin is, that if it hit something that hard, the rest of the blade is probably bent, so at best I would consider it an emergency spare only.

 

[usskydvr]

Re: Broken Tip

So you want to open up your own private one-man prop shop. Going to take a 13 3/4 inch prop and reqork it to a 12 1/2 in. Removing 1 1/4 in of diameter. I sure hope you have some GOOD machining tools. I have those and even then only use the prop for a EMERGENCY spare. I happen to have owned several Tahiti (the single hull ski boat, not the tri-hull) and clones with power from 75 to 150hp. The 17 pitch is about right depending on the motor year ( early motors were crankshaft rated, later years were propshaft rated)normal load, single skier weight, tubing, etc.

 

[FORCE10]

Re: Broken Tip

Thanks alot for all the advice,guess this is one place you don't want to try and save a few bucks huh?i'm going to just leave it alone,throw it in the back and buy a new one.
Time to hit the books and figure out what size to run next,i really need the hole shot and the boats doing 43mph@5000rpm so i think a 15 would get me where i need to go,any thoughts on where this might put my rpm's

thanks,force10

 

[KC4YIN]

Re: Broken Tip

sure you can do that, but as for "getting an idea", no, that is probably not going to help you unless your a pro prop repair guy.
Most prop shops repair them for about 60 bucks and a new one is about 120.
For the best info, get a new one the same as what was on it and go from there. 17 and 19p are the most popular.

If you get the balance off then you risk tearing up the lower unit. Thats not worth it.

I would do what Bifflefan says and just have repaired. Then if you want to buy another and keep one for a spare. After all you keep a spare tire in the trunk of your car for similar situations.

 

[usskydvr]

Re: Broken Tip

I'm all for SAVING money. Trust me, I do LOTS of tricks to do so, but you need to be smart where you choose to cut corners. I suggest you take your prop to a prop shop and have them fix it and change the pitch to a 15. It should be less expensive than buying a new one. Going from a 17 to a 15 will increase your WOT RPM about 350 and give you better hole shot and skier pulling ability.