Ever skied a boat with way too many rpm's?

[6balls]

My buddies kid rocks the prop on his boat lift (TSC-1 Nautique with GT-40). Buddy puts on the spare and we skied it the last two nights. At 34 mph, one guy in boat less than half a tank of gas, no wind, 190 lb skier we are running 3960 rpm's on PP! Like skiing a freight train...every bit of lean is put into acceleration.

I miss passes here and there...but usually it's not a fall. I went out the front twice and once skidding to a spot that could have been in the middle of a neighboring course.

"The times good...the speed is the speed" he says. Umm, no. This is like towing a trailer in third gear vs 5th uphill. One is loaded down, the other can't be budged. Geez at 36 mph he'd be running 4200.

I realize the Nautique 200's with 5.7 run higher R's but they are pushing a big hull...this is all kinds of r's on a little boat...kinda scary.

[drewski32]

My club's 200 runs around 4000 at 34

[Wish]

I will know in the morning what mine runs and let you know since all I will be doing is driving..sounds high though.

[Orlando76]

In my friends 2000 tsc w gt40 I ski 32mph, 200lb, acme 422 prop and it sits at 3440 rpms.

[6balls]

I have to look next time I'm in my own TSC1 but if memory serves I'm about 3450.

[Andre]

What prop did he put on?

[6balls]

Not the kind of guy that can tell you...told me they "looked" like they were the same prop. I've got lots of stories. Good skier, good driver, friendly guy, loves to ski, pretty successful...hard to explain unless you've been around him some.

[rockdog]

@6balls I think for sure it's a different prop to what he had beforehand. 422 is what I have and I'm guessing yours is same as mine for GT-40 TSC1. Runs around that 3400-3450 for memory.

[hogexpress]

My 2000 SN was running 3800+ with an OJ prop and I switched to the ACME and 34mph was yielding 3400-3500 rpm.

[bassfooter]

+1 on the 422 running 3400 - 3500 on a TSC1 hull.

[Steveo]

Same thing happened to me with my 99 Nautique, put on a spare prop and my boat ran faster. 34.2 felt more like 35-36. Set PP to 32.3 and it felt closer to the 34.2 I normallly ski. Come to think of it the spare was an OJ force four I believe. The prop it replaced was the stock prop for that year.

[ntx]

I hope you guys realize that PP is RPM based system. Any time you change your prop you should check and possibly recalibrate the baseline.

[6balls]

@ntx I more than realize PP is rpm based. The shallower pitch on my buddies boat is requiring nearly 4K rpm to hit accurate times at 34 mph. The feel from the skier is very different running 4K rpm at 34 mph vs. 3500 at 34 mph.

If I run my opener on my boat often times I will think the time was slow only to have it confirmed as hot side of tolerance like a mid 16.80's. My opener behind his boat I asked the time and expected about a 16.7 and it was actually a 16.99. Knew I was in for a tough night out there.

 

[DanE]

@6balls Try KX-

[Waternut]

I know what you mean. I ski the course mostly behind a 99 SN and it's probably around 3400-3500rpms at 34mph like most others with a "+" setting. However, my old boat was running more like 3800rpms and even at "n" setting, it would hit me so hard when I went to hookup.

[Alberto Soares]

I have a 2010 Lxi with ZO and 340hp. It was running 34 at 3500 with a 13x11.5 prop, as we are about 1500m (4500') it was bad for taking the skier out of water. Also the ZO was surging at 34mph. I changed for a 13x10.5 prop in order to have the engine working at a stronger torque at 34. It is now at 3900@34, less surging and lot stronger in the starts, in our case a better boat for sure.

[6balls]

@Alberto Soares I can see that at altitude where you need to make more power. Here it's just too much. I would sooner have a 16.80 behind my boat than a 17.00 behind the other one.

[6balls]

I'm telling you brutal. Historically I'm near automatic at 35 off and weeks before this prop mishap was 4-5 balls at 38 regularly with a chance to run it in more passes than not...and sometimes out the end gates. The boat owner often missed his first 35 but then may run 2-4 of them and takes lots of 38 shots but has never run it.

 

Since his prop got trashed and he went to the back up that runs 500 rpm higher at 34 mph...I've run three 35 off passes and missed a ton of 'em usually ending in out the fronts, front flips, and serious handle spits. I typically miss some 35's but never that way...I save that typically for a 38 scramble.

 

Since the prop change the boat owner has been unable to run 35 off. Head vs. tail vs. glass doesn't matter. Last night another skier there who is usually good at 32 off couldn't run it.

 

When ZO came in some asked why not a system that can run constant speed rather than all of this adjustment stuff. This is why. Perhaps I could learn it. A perfectly clean short pass behind it is ok, but a small mistake requiring a manageable scramble have a nice day and relocate some body parts.

 

[Ilivetoski]

Not sure which prop we have, but we have an 04 LXi that runs 3480 at 36

[DanE]

6balls

Seriously, have you tried tampering KX settings?

KX- will tone it down alot.

[thompjs]

Wrong prop, that boat should be 3400 - 3500 at 34mph

[6balls]

@thompjs I know, I have the same hull and same motor. We are pretty regular ski buddies. Hoping he either gets new prop or gets old prop repaired soon.

Maybe I'll offer to split a new one. @DanE no kx/px on his version PP. Original equipment '97 Nautique 196.

When he bought this boat, this prop was on it and we eventually made him change cuz it was brutal skiing...I was a 36 mph guy at the time. No one could ski out there. We measured rope, the course but it came down to the prop. Not sure if that would have been a jump prop back in the day?

Now if this were me (or many of us here), fed ex would have had me a new prop delivered in a day. I need to get him to the swamp so he can knock down some 35's and be convinced it's his prop. Before the prop issue he ran 4 consecutive 35's at his place...not one in the 2 weeks since my guess is he's tried it 20-30 times.

[6balls]

Skied swamp behind my Nautique today...soft and easy tailwind 35. Like slow motion, time to think...nothing like behind my buddies boat.

[GAJ0004]

My boat has the 1:1 tranny with the 240 horsepower 351 Ford PCM, at 36 MPH it runs about 3300 RPM with a skier in tow, and 3100 RPM at 34 MPH. If I got new boat I would put the prop on that would lower the RPM's since I am on a big lake with 700 homes, and would like to quiet the boat down a bit. I would find the happy medium between holeshot, and not having the engine work too hard while going fast to preserve engine life. If I were to buy a new boat it would be the last one.

[Razorskier1]

Trying a new prop on my Prostar. It was running 3900 at 34mph. With a 6.2L I didn't think we needed that. Haven't skied the new prop but without a skier it runs 3400 at 34. Look forward to seeing how it feels.