proper prop?

[Flyone73]

Hello, first time poster. Just picked up a 1997 1801 with a Yamaha 130. Was wondering what you guys recomend for a prop? I had it out t he other day and i was getting about 38 mph with about 4600 rpm WOT. I think that it has the wrong prop on it. But I am a virgin boater, so I really have no idea what I am doing. Actually was the first time I've driven a boat. Any help would be appreciated greatly. I tried looking on the board, but I dont really understand what all the terms mean. Thanks in advance.

 

[BradV]

Not sure what the max operating rpm range is for that motor but assuming its a 2 stroke most are between 5000-5500 rpm at max throttle. So with that being said I would take the boat run it wide open and trim the motor up as high as you can until it starts to cavitate (prop breaks surface of the water and you lose forward thrust) then you will have your max rpm. If the max rpm does not fall into the realm of what it should be then you need to go down in pitch. The pitch that you have on your prop should be stamped on it somewhere something like 14 x 17. 14 would be the diameter and 17 would be the pitch.

 

[Flyone73]

Thanks, so I put on a 13 x 17 and now at wot I am getting 5300 to 5400 rpm. thanks for the help.

 

[DaleH]

I tried looking on the board, but I dont really understand what all the terms mean.

WOT = Wide Open Throttle ... full revolutions or RPMs (Revolutions Per Minute [measured at the flywheel]). WOT is also typically referred to as "Damn the torpedoes, full speed ahead!"

I'd bet your best fuel efficiency and cruise speed would be from 3800 to 4400 RPMs, PROVIDED you're wearing the correct prop.