Trouble pulling skier out of the hole

Kweaver

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Jun 15, 2021
Messages
15
How many souls were onboard when the atlethic skier couldn't get out of the hole fast enough ? What's the min-max wot rpm range factory stated for that IB ? Once it's known , go for a wot run with only 3 up and report the max rpm achieved ? Need to prop right that motor to run towards it's max wot rpm range to get the skier out of the hole much faster...

Happy Boating
I only had myself and one other person on the boat, and that person was sitting at the very front of the boat, so number of ppl shouldn't have had any bearing. No idea what your other questions mean, sorry.
-min-max wot rpm range factor setting? I know what rpm is, not the rest.
-go for a wot run?
- how do I prop right?
I attached the prop I have above. I have a 4.3 Mercruiser engine that I believe is a 220 or 225 hp. That's all I know. Again, not brand new to skiing, but brand new to owning a boat. And, there is no way it should take the skiier as much effort as it is taking to get pulled up. My jet ski gets them and me out of the whole better than the boat.
 

Sea Rider

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Sep 20, 2008
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All motors whether being in or outboards have a min and max wot rpm range factory stated, the motor musn't rev at the min side or will lug the motor badly which it's no bueno. I's like going up hill from a dead stop geared at third gear.

OTOH must not pass the max wot rpm range, both min and max ranges should be dialed as usually loaded. Will be good to know the wot rpm parametrs for that motor and go from there. Go for a wot run means going full throttle ideally on flat calm water conditions with motor well trimed.

Propping right means dialing a prop that will make the motor to rev towards it's max wot rpm range, which isn't known for skier to benefit achieving top hole shot. Does the combo have an installed tach ?

Happy Boating
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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No such thing as one prop fits all. The prop you use for watersports is always 2-4 " of pitch less than your cruising prop.

Suggest dropping down in pitch.

However in the mean time, move everyone to the bow, trim all the way in. Dont trim up until the boat is out of the hole. Dint have people move aft until the boat is out of the hole

When I had the Anavti with a 3.0, always needed to move people to the bow to get the boat out of the hole pulling skiers If that turd of a motor could pull my 280# buddy up on one ski, your 220hp 4.3 will pull up your 175# bud on two skis
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Sea Rider

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Before dropping in pitch or adding more blades will be good to know the OP's current wot rpm achieved as loaded with current prop, that's what tachs are for. To have extreme fun while skiing don't need to have more than 3 souls on board, that's what the expert skiiers recommends...

Happy Boating
 

Chris1956

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Mar 25, 2004
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27,036
That 21P prop may be a bit too much pitch for your boat/motor combo. Your motor should develop the necessary power with that prop, but it may not be the best or fastest to do so.

However, I think your technique is just as much to blame. What you should do is trim the motor in all the way. Trim tabs should be down, if you have them. Tighten the slack in the tow rope. When the skier asks you to hit it, push the throttle all the way forward. Don't just slam it, but move it smoothly and quickly to WOT.

Now watch the RPMs. As they pass 3000RPM, start to throttle back. You want to pull him at 36MPH for Slalom and 32MPH for 2 skis. See what RPM achieves those speeds and throttle back to that. Ideally, you want to have the throttle all the way forward at the start, and throttle back to meet the intended RPM, as you reach it.

Pulling a skier well has a lot to do with being smooth and predictable on the throttle and smooth on the steering.

If he still hates the pull, get a 19Pitch prop. 3 blade or 4 blade prop will make no major difference.
 

Kweaver

Cadet
Joined
Jun 15, 2021
Messages
15
That 21P prop may be a bit too much pitch for your boat/motor combo. Your motor should develop the necessary power with that prop, but it may not be the best or fastest to do so.

However, I think your technique is just as much to blame. What you should do is trim the motor in all the way. Trim tabs should be down, if you have them. Tighten the slack in the tow rope. When the skier asks you to hit it, push the throttle all the way forward. Don't just slam it, but move it smoothly and quickly to WOT.

Now watch the RPMs. As they pass 3000RPM, start to throttle back. You want to pull him at 36MPH for Slalom and 32MPH for 2 skis. See what RPM achieves those speeds and throttle back to that. Ideally, you want to have the throttle all the way forward at the start, and throttle back to meet the intended RPM, as you reach it.

Pulling a skier well has a lot to do with being smooth and predictable on the throttle and smooth on the steering.

If he still hates the pull, get a 19Pitch prop. 3 blade or 4 blade prop will make no major difference.
I don't disagree that technique might have something to do with it. But something seems off with the boat. I'll get to that in a minute.

First, what does WOT mean?

The trim has been all the way in every single time and the slack has been tightened, as I am actually slightly pulling him along before he says go.

I have tried several ways in pulling him up. I have slammed the throttle down all the way, and the boat does not pull him up quickly, and it did seem to yank the rope.

So, next, I felt like I was pushing the throttle all the way forward, but more smoothly and quickly like you say versus slamming it down, when I did this, he does come up eventually with a lot of effort on his part, but by the time he is up, the throttle is all the way down, but not going fast at all and he is motioning the entire time to go faster because he is literally about to sink/fall because the boat isn't getting up to speed.

Now, on to how I don't think the boat is acting right. We put it back in the water yesterday, and I just took it out to look at the RPMs. It was only me on the boat. I have attached videos of the panel. Hopefully, these videos will help.
 

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Kweaver

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Joined
Jun 15, 2021
Messages
15
No such thing as one prop fits all. The prop you use for watersports is always 2-4 " of pitch less than your cruising prop.

Suggest dropping down in pitch.

However in the mean time, move everyone to the bow, trim all the way in. Dont trim up until the boat is out of the hole. Dint have people move aft until the boat is out of the hole

When I had the Anavti with a 3.0, always needed to move people to the bow to get the boat out of the hole pulling skiers If that turd of a motor could pull my 280# buddy up on one ski, your 220hp 4.3 will pull up your 175# bud on two skis
I only had one other person on the boat with me and they were at the bow. Trim was all the way in, and I didn't trim up till the skier was up. No one ever moved.
I agree, this boat should be able to pull him up, but it takes way too much effort on his and the boats part.
 

Kweaver

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Jun 15, 2021
Messages
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Before dropping in pitch or adding more blades will be good to know the OP's current wot rpm achieved as loaded with current prop, that's what tachs are for. To have extreme fun while skiing don't need to have more than 3 souls on board, that's what the expert skiiers recommends...

Happy Boating
Hopefully the videos I just provided help. I didn't have a chance to pull the skier yesterday, so when I do, will take another video.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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WOT is Wide Open Throttle. that is the throttle control against the stops

your boat with only two people on board should pop out of the water on plane almost instantly when you mash the throttle.

pulling a skier, as indicated above, is just slightly less of an instant mashing of the controls forward, however a quick move forward until the boat is out of the hole

if something is off in the boat as you are stating, start at the beginning

  • what is your compression numbers across every cylinder? (should be between 140 and 150 psi)
  • what is your fuel pressure both at idle and at full load at WOT? (should be 43-45psi)
  • did the flappers drop blocking off your exhaust?

I would still back off the pitch on the prop. not enough torque from the motor and a bit too much of a prop bite will have the motor on its face as well as the skier. remember the 220hp isnt until that motor is at full 5000 RPM.

the 4.3 is a great motor, however it lacks the low-end torque of the V8's. the drive ratio helps a bit, however if you are not bouncing the motor off the rev limiter at WOT, you are over-proped for water sports.
 

Chris51280

Master Chief Petty Officer
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Jan 24, 2018
Messages
897
there is definitely something off. the one video shows 5000rpm and hardly moving and the other shows 3500 max with 25mph.
either something is off with the engine like not firing on all. I had that. was running on only 4 cylinders had only half the power.
the other is the prop not being the correct one. you seem to be able to go to 5000 rpm but hardly under way.

the videos are not consistent
 

Chris1956

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Mar 25, 2004
Messages
27,036
Looking at the videos....your tachometer jumps all over the place. You are still idling and it jumps over 3000RPM. I suspect it has wiring issues or is broken.

Secondly, at full speed, the tach shows 3000RPM. I cannot tell what speed you are going, but if the engine doesn't go over 3000RPM at full speed, you have an engine problem or your prop has way too much pitch.

The boat should be propped to reach 4400-4800 RPM with a standard load of people and gear.

Not sure I can offer anything else as there are too many unknowns.
 

Kweaver

Cadet
Joined
Jun 15, 2021
Messages
15
Looking at the videos....your tachometer jumps all over the place. You are still idling and it jumps over 3000RPM. I suspect it has wiring issues or is broken.

Secondly, at full speed, the tach shows 3000RPM. I cannot tell what speed you are going, but if the engine doesn't go over 3000RPM at full speed, you have an engine problem or your prop has way too much pitch.

The boat should be propped to reach 4400-4800 RPM with a standard load of people and gear.

Not sure I can offer anything else as there are too many unknowns.
I appreciate all the help! I have felt like more was off then just driver error, so nice to have someone else check things out. Thanks again!
 

Sea Rider

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Sep 20, 2008
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12,345
Check if the tach it's doing its homework right, has an erratic jumpy needle behaviour. If all good the motor loses revs very fast when at wot which will not maintain a skier up for too long...

Happy Boating
 
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Can you explain what you mean by pitch of the prop? I have a 3 blade, but no idea what the pitch is or what that means.
Pitch is the angle of the 3 blades. They make the same diameter propellers with different angles of the blades... called pitch.
 
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