2014 Yamaha 25hp Alumacraft Prop Choice

[Jrivas13]

How's it going? I just recently picked up a 2014 Alumacraft Escape 145CS with a Yamaha F25LA. It was very clean and read 26 hours on the tachometer. Boating around for the first time with 2 guys felt fine showed 23 mph on garmin gps. Long story short over 4th of July took family out (4 people total) and the boat wouldn't go over 8-9 and just plowed water. That was fun for all about 30 mins. That's when I started reading about getting a prop for heavy loads and a prop for when I go out fishing (lighter loads). But I had no rpm specs for eitheir trips. So I grabbed a friend and went out tonight to grab some specs on the lake and here's what I came up with. Prop now is 9 7/8 x 10.5", speed 23 mph, Rpms 4000-4500 wot across lake. Spec should be 5000-6000 wot correct me if I'm wrong? But can this be cured with a different prop? If so what would you suggest? Or possibly a engine issue even though having such low use? Let me know your take on this. THANKS! -Joe

 

[Sea Rider]

Welcome to Iboats,

Will need a much less pitch prop to pull wot revs up. Wot rpm for that OB should be 5000-5000 not 6 K, check Yam specs to be shure.

Which OEM less pitch props are currently available ?

Happy Boating

 

[Jrivas13]

Hey thanks for getting back, Yamaha offers a 8 or 9 pitch prop same diameter. I did also notice that the hydro foil fin is about 2" lower than the lowest part of the hull. Would that play a factor in not reaching my wot rpm as well? I bought this privately but the previous owner had this outfitted by cabelas.

 

[Sea Rider]

If OB produces back or over transom water splashes, definitely will lower max wot rpm achieved due to excessive water drag. Check if with issues at back transom. Report your findings...



This is what you need to dial for OB to rev happily, from there can go for a prop maximization to a 8-9 pitch prop.

Happy Boating

 

[Jrivas13]

 

[Sea Rider]

Thanks for posting water results,

Is yellow line on new posted pic is where water flow passed at speed/plane provided that OB was trimmed to 90?, OB is at the middle of nice/mediocre water performance. Is it possible to lower OB without the need to chop transom down or add a jack plate ? Go for a wot spin, make close turns at speed, will assure that OB will experience prop aeration issues as of now.

Happy Boating