newbe question on pontoon boats.

[chuck67207]

ok guys wife talked me into it, bought a 2006 21ft sedona with a 50 hp yamaha, took it out for the 1st time, noticed it was turning only 3800 rpm. it has a 121/4x9 pitch prop that came with it. is that sound right, just seems a little to low to me, iam use to my bass boat a skeeter with a 150 hp. haha i know its alot different, and going to take alot of getting use to. was wondering if i went to a ss prop if i could a little more rpms out of it. told the wife i needed a new 90 hp 4 stroke but she wont see it my way haha. need some help just seems so slow. the book says it should turn 4500 at wot. i know its tasking that little moter is that all i can get out of it? thanks chuck.

 

[5150abf]

Re: newbe question on pontoon boats.

That does sound a little small, I have a 50 on a bass style boat and run a 12 1/4 x 15 but before you buy a prop confirm the engine is running as it should, you will never prop a bad a running engine.

Witha prop that small it seems like it should be over revving if anything which makes me suspect the engine isn't running at full power.

 

[Silvertip]

Re: newbe question on pontoon boats.

I take it the motor is a "High Thrust" model. The props is a 14x9 (14 inches in diameter with 9 inches of pitch) and that sounds about right. I would first verify that the tach is reading correctly. Very often the number of pulses switch on the back of the tach is set incorrectly. If that is fine, then there is a power issue -- not a prop issue. The manufacturer recommends a wide open throttle rpm of 4500 - 5500 rpm. Practice is to prop a boat so the engine is at or very near the UPPER end of the rpm band with what you consider an average load. I really feel you have an engine issue. 50 HP on that pontoon is just fine and should deliver about 18 MPH -- maybe a tad more with a light load.

 

[nor2345]

Re: newbe question on pontoon boats.

I'm running a 2009, 50 hp Yamaha, 4-stroke, high thrust on a 20ft. Bennington. The prop is a "Dual Thrust" 14'aluminum with an 11 pitch,made by Yamaha specifically for that motor. I hit a rock with it and sent it off for a re-build. Put a Solas, Amita 14'x11 pitch to get around until I get the Yamaha prop back. The Solas dropped my max rpm from 5200 down to 4700. Same weight, same conditions. Max. speed dropped from approximately 19-20 mph down to about 15-17mph. I noticed a significant difference in acceleration both forward and reverse. The Yamaha prop is definitely superior. Cost for the Yamaha: $181.00 +tax $16.00 = $197 (no shipping the dealership has them). Cost for the Solas: $109.00 + $17.00 S&H + tax $10.00 = $136.00. A $61.00 difference. I tried to locate a re-built prop but, no shops in my area had one. Cost for a re-built around here (north-central Arkansas),is around $50.00 - $60.00 + tax. Is the Yamaha worth it? Since I know how much better the Yamaha performs over the Solas, yes.

 

[chuck67207]

Re: newbe question on pontoon boats.

thanks guys, i had my good friend look at it with me he is a boat mech plus a drag boat racer. we worked on it all nite finally found the problem. 1 st thing was the tach, they had it set for a 8cyl moter, 2nd thing was the carbs wasnt opening up all the way. after about 2 hrs looking and trying differnt ajustments, figured it out. the manufacture had the control box all messed up had the throttle cable on the wrong ear. got right now have full thottle and even sounds like a new moter. cant waite to try it out this weekend. the compression test was also good. now i can prop the moter like it should be. thanks for the help guys. chuck.