Prop question/suggestion/problem

So want to say thanks in advance for you guys letting a not CC guy ask questions on here.
So the motor I have is a 350 efi with 260hp I think. On the motor it says max rpm 4400-4800.

Remember im also in denver so im at 5280 elevation.

Ok so my old prop was a 13x13 oj that has some dings in it. I think we gps it at 40mph one time and im not sure what the tach said.

So just bought a acme 541 from hollywood. The thing looks great, looks brand new and he did an awesome job shipping it out quick.

So I put it on and got my first run today and we were at 40.5 or so mph. That is with half a tank and 2 ppl in the boat. When my buddy went in the back we touched 41. The rpm was at 4200ish maybe a touch over that not 4300 tho.

So now Im wondering what you guys would recomend for a prop with those numbers I just gave you. Just to refresh your memory the 541 is a 13x12. Another option is the 543 and thats a 13x11.5. Im also wondering if I could go to a 13x11? I dont know anything about props I could be going the wrong way here. I do know acme says the 543 should give you an extra 150 rpm or so.

Thanks again

Thanks for the info. My footing partner used to have a 79 MC and stock prop here in denver got him 39 and with the 541 it got him 42. I mean you should be able to get the max or close to it rpm out of your motor if you prop it right. I am willing to sacrifice hole shot a bit if it means I can one foot. Through the slalom course and get up it did do great. I was really looking for some more footing speed.

Ok so Update. I have been having this idle problem where it would idle fine and then when you reved it up it would not go down past about 1500 rpm. So when trying to figure that out we noticed the perfect pass cable was too short to allow the throttle cable to reach full throttle. Also the idle problem was the cable pivot end, the part that connects the throttle cable to the throttle control, is worn about half way through. So I swapped the end with the transmission one (just for this weekend will order some monday) and I put on the regular piece that connects the throttle cable to the throttle body. After a bit of adjustment it worked perfectly. Also (I put the stock prop back on so that i did not dent the new one for some stupid reason) so with running the stock prop it got me almost 100 more rpm and it went from 40mph to 42 mph so tomorrow morning im going to put on the 541 and test it. I think I will like it after all.

Do you ski the Pits?

lcgordon wrote: . Maybe the 543 or the 912 like TRBenj suggested. Its pretty frustrating

If your running a left handed prop you'd want a 913 like Tim suggested. A 912 is a righty. I just got a 913 from Delta a site sponsor for $346. Took several weeks,they did not have it in stock so they had to order from Acme.

lcgordon wrote: Yeah I looked it up and noticed that. I just thought the 541 would change my life like ppl said it would. I noticed zero difference and it may have been a bit worse. Just may be my boat i guess.

Keep in mind Landis, you're in relatively foreign territory. Trying to get prop or carb help for people at sea level comes pretty easy for us after quite a few years of experience. 5280' is quite another story. We're learning just as you are.

FYI, when I was doing prop testing for my AmSkier my stock Federal prop was a 13x12 that was repitched and rebuilt to 13x13. I turned that sucker 5800 and got 55MPH out of it but it pretty much just sat there boiling water until I let off of it a little and had to ease it out of the hole to WOT .
After trying virtually every version of OJ available and a couple different ACME's none of them could match that 55MPH WOT speed. They came close but none matched it. Virtually all of them had much better performance through the entire RPM range though. Some better then others.
The guys at AmSkier finally got smart and started putting 13x13 props on the boats from the factory (vs. the 13x12) like they should have always had. The point I'm trying to make is that the factory prop on these AmSkiers is pretty good already and the noticeable performance improvements experienced by CC owners is not going to be the same. It's still a completely different hull.
Improvements can still be made however and virtually every AmSkier running the proper ACME prop experiences better OVERALL performance then the factory wheel. All it takes is a little experimentation.

You're also at a big disadvantage already being at altitude with a bone stock 260HP engine. Yet you still want it to be able to run 42-43MPH for barefooting. I would be really surprised if any similar boat can do that without some some serious engine mods or having a stock engine running significantly more HP.
Keep working at it with the best guess knowledge you'll find here. I'm sure you'll find a better wheel then the factory. I just don't know that you'll find the results you're truly expecting but I also truly hope I'm completely wrong.

Thanks guys for the help. I know nothing about props and the MC guys love the 541. My buddy had an older MC and it gave him 3 mph and his rpms were at his max. So I thought it would help my boat. The thing that has got me is that my boat turns more rpms with the stock prop and also gets a higher speed. I mean we are talking like 50 rpm or so so there is alot of factors like wind chop and driving in which direction on the lake and stuff but by the calculations 13x13 to a 13x12 should give me 200 or so more rpm. Atleast once I took the too short of perfect pass cable off it did give me an extra mph tho and I could notice it while footing. Im not doubting you guys that my boat may just not be able to get what I am wanting, I am just confused because everybody says that I should have gotten better results by atleast a little over my stock prop. Oh well time to just be happy with what I have.

1994 American skier Tbx

Its a budget boat. I dont make much money and denver is expensive to live in. For footing out here I really need an outboard. An old Barefoot warrior with a 225 should do. Maybe someday.

Nope. We were over this in another thread. Maybe the barefoot thread. It's a EFI SBC and exactly the reason why I'm such an anti-EFI guy. They're awesome at self adjusting to virtually all conditions but you get what you got. Adding HP is not a cheap option like you can do with a carbed motor.

My bad, assumed it was a carb motor.

You're a couple years late, Once upon a time I had a 1225, 1609 and 543. Have you found any avenues to demo?

1609 looks like a 543 with .020 less cup. He's probably close on the 4550rpm guess.

Since you're a footer and really care most about top speed under a load, I'd be aiming towards the higher end of the range (4600-4800) when unloaded. Hence my 913 advice. 4550 is a step in the right direction but still comes up short.

Hollywood wrote: You're a couple years late, Once upon a time I had a 1225, 1609 and 543. Have you found any avenues to demo?

Bummer I need all of those! and with acme I can buy and ship back so I guess you can call that demoing.

TRBenj-Thanks for that post it pretty much sums up the basics of what I need to know. I will try to keep trying until shipping props gets too expensive. On a positive note I have learned how to change a prop pretty well ( not that there is anything to it). I need to get a big box of cotter keys trying to straighten them and get them back in is a pain and probably weakens them and is not the best thing to do incase something did actually happen.

Btw I love the suit you sold me it fits me perfect and is really easy to get on.

Thanks for that Ill do that.

Ok thanks Ill give them a call. and see what they say. I really hope I can get away with one more prop buy because at 20 bucks a pop to ship it gets a bit expensive to do alot of it. Its worth it to get some toe hold tho I guess. The shoes are fun but Im ready for barefeet.