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Set the turn fin so that the top of the fin is parallel with the top of the sponson.
If using an adjustable strut, set it flat on the ski (0 degrees).
Set the rudder so that the right side is parallel with the tub (slight left trim).
Set rudder throw to
10 degrees right and left
. Use the least amount of throw on the servo arm,
and use your radio’s ATV or end point adjustment to reduce it further. Do not exceed these
throws!
Run the boat. If it looks loose at full throttle, adjust the fin angle back slightly.
Measure from a convenient point, like the rudder. Adjust the fin 1/16 inch, no more.
Do not exceed 1/16 inch increments. The fin adjustment is very, very sensitive, and it is easy to
go too far.
As you adjust the fin forward, the boat rides loose, and adjusted back, the boat rides wet.
Don’t try to shim the strut right or left. This does nothing.
Tips
Do not change the ride attitude or height. Leave the AOA alone…
The boat will not turn sharp left. You can make left corrections, but if you push it, it will flip.
Try different props. The ABC 2818/2 R (round tip) is a good start.
Do not cut the rudder. You need all you can get to control prop walk.
If you are running a larger prop than 2.8 inches (71 mm) due to a high torque engine, you may
experience excessive prop walk. This is simply because there is not enough rudder in the water
to prevent this.
To counter this, you can mount a small fin to the rear part of the ski. We can supply this free of
charge if you need it. Just contact us.
When you finish your rigger, why not send us pictures for our web site?
We would love to see them.
Pictures of the boat sitting in the water are our favorite…