Posts: 3480
Location: Elk River, Minnesota | Good Morning!!
Couple of questions for you to start out. First, when you are running the 5100 - 5200 RPM's, what is your load like (People, gear, etc) Also, what hole position is your motor in (#1 hole is lowest motor position with the motor flat to the transom). With this little bit of information, there are a few things that can be recommended to try which might involve a prop change as was mentioned.
My gut instinct says you are overpropped as well, but I have a feeling that a 19 pitch might be a bit much yet. Each inch of pitch will add/reduce roughly 200 RPM's, so going with a 19 pitch theoretically would only get you to around 5600. With a motor height change, though, you might tweek out 5800 by going up a couple holes, which on that boat, should be a positive change. Most V-hulled rigs like yours can have the anti-ventilation plate about 2 inches above the lowest part of the hull and still have great handling and definitely more speed. There is a limit to everything, though, which means as you move the motor up, a slight decrease in handling and more ventilation can take place.
I should also ask...is the prop you have a black stainless prop? If so, I would highly suggest trying different props. The yamaha pro series propellers are outstanding props for both bite on the water and for higher motor heights (which I have a feeling will be something to get more RPM's as well) If you can find a good dealer that has demo props, I would see if you can get 3 or 4 different ones to try and head to the lake for testing. One will stand out well above the others which will give you optimum speed and lift, which will make the boat just float along at cruising speed, and really perform well at high speed.
Lots of variables in this, but if you enjoy tinkering, this is a fun project.
Steve |
