Need prop help

[crash14me2]

Here we go , got a 17' 6" lowe aluminum boat. A yamaha 115 2 stroke with a 13x19 ss prop. At 3/4 throttle it will turn 5000 rpm. Thats max rpm on that motor. Thats with 3 people and coolers, loaded. Worse when empty. Boat will jump out of water on take off very easily. Also seems to feel like there is a small amount of "slip" just before it planes off good. Kinda feels like it grabs after initial throttle up. Any ideas?

[javelin99]

Crash,

You may want to check your owners manual.I think the max rpm is 5500 on that motor

[crash14me2]

Maximum output:
84.6kW @5000r/min (115hp@5000 r/min)
Full throttle operating range:
4500-5500r/min
What ya think? Also doesnt explain the slipping feeling.

[javelin99]

On my new sea hunt 207 I have a 150 2 stroke.iIhave a 15.5x17 pitch ss prop& it runs T 5500 rpms at wot. It also jumps on plane just as fast as my bass boat did.I don't think the dealer would put the wrong prop on the boat You may get a better answer if you post on the hull truth

[Hawkeye]

crash14me2 originally wrote:
Here we go , got a 17' 6" lowe aluminum boat. A yamaha 115 2 stroke with a 13x19 ss prop. At 3/4 throttle it will turn 5000 rpm. Thats max rpm on that motor. Thats with 3 people and coolers, loaded. Worse when empty. Boat will jump out of water on take off very easily. Also seems to feel like there is a small amount of "slip" just before it planes off good. Kinda feels like it grabs after initial throttle up. Any ideas?


How high is the engine mounted, where is the anti vent plate compaired to the boats bottom? Do you have a fish finder transducer mounted within 12" of the engine? Or a thru hull pick up mounted in front of the engine? You do have the engine trimmed all the way down on powering up and then trimming it out some after you are on plane? It does not take much to cause a prop to ventalate. If your engine is rated to turn 4500 to 5500 rpm I would set it up for the prop to turn 5500 with a light load. This will allow you to load it down and still run up to 5000 rpms.

[crash14me2]

Were you on the river last saturday? Thought i saw a new boat as you described.

[javelin99]

crash14me2 originally wrote:
Were you on the river last saturday? Thought i saw a new boat as you described.


I passed you near Jordan Point as you were going down river around 2 oclock

[spin-a-bait]

hey Javelin99,my boat jumps up on plane good doesn't it??lol.....

[javelin99]

spin-a-bait originally wrote:
hey Javelin99,my boat jumps up on plane good doesn't it??lol.....


It gets on plane fine with a 69 in the livewell

[crash14me2]

javelin99 originally wrote:
crash14me2 originally wrote:
Were you on the river last saturday? Thought i saw a new boat as you described.


I passed you near Jordan Point as you were going down river around 2 oclock


Next time wave me down. Would like to check out the new ride. Didnt know it was you otherwise would have atleast waved.

[Hawkeye]

Crash, you ask for prop help? Guess you got it figured out?