Posts: 3472
Location: Elk River, Minnesota | Hiya!!
There are a few things that can make huge differences in how a particular motor pushes a rig. First and foremost, the mounting location of the motor. In most cases, when motors are mounted to the transom, they are mounted for the purpose of overall running (handling and "decent" speed) but usually that is not the most efficient location. Many times the motor is mounted 1 bolt hole up off the transom, and this usually means the anti-ventilation plate is under the water's surface, which is a huge amount of drag. The boat will turn really well, but just doesn't float along while at cruising speed or really lift out of the water at high speed.
If you can, level the hull to the earth, then level the motor to the earth and take a picture. Let's start with what the rear end looks like by comparing the hull to the anti-ventilation plate.
The second big issue that may be happening is not trimming enough. I am assuming you have found your numbers here based on just you and your equipment (3/4 tank of gas) trimmed to the best position you can for speed.
With that size of motor, a 21 tempest should push it along close to 60 as has been mentioned, so my gut instinct says there is something up with the set-up of the motor, prop and boat.
The prop itself....Do you have the vent holes completely plugged, partially plugged or wide open? If wide open, that might be too much ventilation, and the prop is not grabbing well enough for a great hole shot.
That boat is balanced quite well for weight on it's own so a 3 blade should be all you need. If you are in the twin cities area, I'd give you a hand as well...
Steve |
