prop-ing for a skier, but too much rpm when not skiing

My Gf has a 175 bayliner 3.0 inboard. I think it is 140 hp.

they use it for fun... her son like to wake board, and she likes to ski.... many times they have four people in the boat besides the skier..but usually at least 2 other people and the skier..

the boat is OK>>> when they pull the son up on his wake board... as he is pretty good at that..

but the boat has a hard time pulling my GF up onto her solo ski, that she likes to use.

she isnt heavy at all either!!!! ha ha..125 lbs...

the boat really dogs out and squats...but I THINK, they are running the right rpms at WOT now....4500-4600 when trimmed and running along.

so my question is, can we drop down in prop pitch to help with starting a skier, even though the WOT rpms will be too high....AS LONG AS THEY DONT WIND THE MOTOR OUT TO THOSE RPMS??????

so we will get more bottom end, but wont push the throttle to the max...

is that acceptable???

or do we have to get creative with a special prop, and weight distribution????

or add more HP???

she asked about a prop and so i figure Ill try and find out for her..

BOB

Re: prop-ing for a skier, but too much rpm when not skiing

You can go with 2 props, one for pulling and one for empty, to be safe. Else, there is no issue keeping a single prop with lower pitch, and be careful not to exceed max rpm when empty.

Another idea is to switch to a 4-blade prop; rule of thumb is drop 1" in pitch. If the max engine rpm is 4800, drop 2" when going with the 4-blade.

Curious, what is the prop size currently on the boat?

Re: prop-ing for a skier, but too much rpm when not skiing

Ill find out soon.....what ever is standard , i imagine when the market the boat...

I bet a 19 pitch ....

thanks

bob

Re: prop-ing for a skier, but too much rpm when not skiing

the max rpm they have hit with the prop they have now is 5000!!!!!!!!! and it is a 21 pitch!!!


so i dont think there is much they can do....they are at max rpm if they dont ski , and just run around the lake,.....and if they do ski, they will just have to deal with it...they need a bigger motor obviously!!!


bob

Re: prop-ing for a skier, but too much rpm when not skiing

At 21" Im not surprised it struggles with a slalom start.Be sure she keeps her weight forward knee bent balance with the off foot don't press down on the back of the ski.
While it is possible that it could run at 5,000 w a 21 it is unlikely especially if that is with the typical load is in the boat.You may want to varify the tach is accurate.A 21" pitch at 5,000
would probably run 44 mph.or more.
You may be able to borrow a shop tach to check the rpm.
Check the switch on the back of the tach.note the position and operate it a few times to clean the contacts.I couldn't find a 140 but the 135 is rated at 4600.
Verify the tach If its accurate at 5,000 you could go to a 22" 4 blade.
The 4 blade will help get her up.More likely the tach is off.
Let us know what you find.