mercury EFI60hp

cheeseboat · 26 August 2018, 10:41

Hi all, forgive the ignorance in this request but I am new to all this.
I’ve got a small rib with a mercury 60 on it. It goes really well but.... I want to get a person weighing 100kg up on skis. Please don’t worry about carving etc, that will come later...
What aspects will most effect the ability to “get them out of the hole”?
Engine revs to about 5800rpm WOT
I haven’t take the prop off to check the pitch but attach photos for info.
What happens if I change pitch and diameter?
I understand if I drop pitch I need to be careful at WOT not to over rev.
Does a longer rope make it better or worse?
Part number on prop says 71314A45
Sticker on engine says 12x22 1.83:1
See pics

Click image for larger version

Name: IMG_3362.jpg
Views: 242
Size: 90.6 KB
ID: 126554

All advice appreciated.

cheeseboat · 26 August 2018, 10:43

It gets a 75kg up

chipko · 26 August 2018, 11:14

Hi,
Looks like you have a Mercury Black Max 10 5/8” dia. x 12” pitch prop.
We have a small 5m rib and Mariner 60EFI which we’ve propped for towing with a 10 3/8” x 13” Flo-Torque II Black Diamond 73136A45 prop.
Gives us good hole shot and maxes out at 6000rpm, sacrificing a little top speed but manages 38mph/33knots on a good day one up.
Going down 1” in pitch gains around 200rpm usually. Seems odd your not maxing out on revs with a 12” prop.
Sticker on leg is just the gear ratio.
Difficult to over rev as it should just bounce off the limiter.

Last Tango · 26 August 2018, 12:01

If it's a novice skier that's struggling a pair of "planks" (flat bottomed skis) will come up easier.

cheeseboat · 26 August 2018, 12:20

Quote:

Originally Posted by chipko

Hi,
Looks like you have a Mercury Black Max 10 5/8” dia. x 12” pitch prop.
We have a small 5m rib and Mariner 60EFI which we’ve propped for towing with a 10 3/8” x 13” Flo-Torque II Black Diamond 73136A45 prop.
Gives us good hole shot and maxes out at 6000rpm, sacrificing a little top speed but manages 38mph/33knots on a good day one up.
Going down 1” in pitch gains around 200rpm usually. Seems odd your not maxing out on revs with a 12” prop.
Sticker on leg is just the gear ratio.
Difficult to over rev as it should just bounce off the limiter.

That’s really helpful info, thanks so much for taking the time to reply.

cheeseboat · 26 August 2018, 12:21

Quote:

Originally Posted by Last Tango

If it's a novice skier that's struggling a pair of "planks" (flat bottomed skis) will come up easier.

It is a novice so I’ll try some planks too! Thanks