What prop size to use

[Mike Harry]

The boat came with 2 props. One is the prop that was on the boat and is marked 13 x 12 (or 12 x 13) I dont remember. The other is marked 13 x 13 and is brand new. Both have 3 blades.

Which one should I use? The one that was on the boat is a little beat up so I am hoping you all say the 13 x 13

What difference will it make either way?

[Midskier]

use the one that gives you the best performance............ typically 13 x 12 is used to increase wide open throttle (WOT) rpm, increase hole shot, increase response @ between a certain rpm range, allow "normal" running quality under a heavier load......... Barefoot boats used @ barefoot tournaments have to carry a drive and 2-3 judges - plus the skier @ their desired speed, 13x12 and a strong engine did a better job @ that task than a 13x13, 13x13 is the most common size for straight inboards with 1:1 trans a clean 13x13 will generally provide better overall running qualities @ more reasonable rpms than the 13x12
if the 13x13 makes the boat a total dog maybe you have another issue (water soaked flotation foam)............. if she runs fine leave it if your loading your boat up with fat sacs use the 13x12
the difference between the 2 would be about 400 or so rpm @ WOT

was that clear enough?

Dan T
Midskier

[Mike Harry]

Yes that's perfect. Thanks. Now, can one of these be reconditioned or is it just buy a new one? Ill trade a brand new 13 x 13 for a reconditioning job on my 13 x 12. What do these things usually run price wise? Better to buy stainless or the cast?

[Midskier]

good question

depending on how bad the mangled prop is and how good your prop shop is will determine if repairable or not
most of the time the few dings here and there can be fixed, a missing blade....... buy a new one

a new acme 541 is almost $450,  I just had a few fixed up, they were about $150 each

stainless.......... not many in the inboard stainless prop game solas branded props seem to be around, I think
they may have taken over cutter(?) both are foreign made I have not had an issue with either one
and they currently cheaper than the acme

I'll spend your money as if it were my own............I'd put the 13x13 on for now
get the 13x12 fixed and swap it back out if the 13x13 does meet your needs, if it does ok, I'd leave it
and keep the fresh 13x12 as a spare.

you can send me a few pics of the 13x12 first, if I think it's repairable you can send it here ........

one more prop note for everyone else:  There are some things you can beat off..........but a prop is not one of them!  USE A PROP PULLER!

Dan T

[Mike Harry]

I checked with Solas...... only 13x13 no 13x12 so I guess that stainless is out of the question.

Dan I sent you some pictures from my phone, dont know if I did it right. I hope they get to you.

How do I tell what size the shaft is? Micrometer?

I guess Im just hoping that my prop can be reconditioned.... that would be the easiest way to go for me. There are so many sizes and brands with different materials out there it is getting a little confusing.

[Mike Harry]

I am going to try the 13x12. Sent it out today for reconditioning.  What is the install process? Any torque settings? Just ram it on with an impact? How do I, or do I try to stop the shaft from moving?

[RonT]

NEVER just ram it on, that is when the keyway will slide forward just enough to keep the prop from seating properly, then when you tighten the nut you will distort the keyway & your screwed & cussing at yourself. Heres how I do it:
1) position the shaft so the keyway is up
2) slide key in slot to make sure it slides easily, if not file key till it does
3) slide key in & out of prop slot, if not file the key til it does
4) place key on shaft
5) carefully slide prop over shaft with finger on the back side over the key slot to feel
6) make sure the key doesn't "grab" and slide too far up the shaft
7)prop should feel "seated" into the taper
tighten nut with a block of wood wedged against the hull bottom & prop
9) I have never used a torque wrench before on a prop shaft but I would guess I'm applying 60-80 ft. lbs. of torque

[Mike Harry]

Took your advise Ron, slid on like a dream. Cant wait to see it spin!