Traxxas spartan shimmies at full throttle

[RotimusPrime]

My buddy bought a traxxas spartan and at full throttle the boat shimmies back and forth really fast. Why is this? How do I fix the problem?

[Fluid]

This is chine walk. It is caused by a deep vee mono running too far out of the water. Not enough hull is in the water for stability and any disruption can cause it to rock back and forth trying to balance on the sharp keel.

It can can be solved either by running slower, or by lowering the hull deeper into the water, usually by raising the strut. Trim tab adjustment very seldom does much.


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[fweasel]

Raise the strut as much as the setup allows. You might be able to slot the mounting holes. There's a fair amount of play since the stuffing tube stops at the transom and only the flex cable exits. That, as Fluid mentioned, helps put more hull in the water. I ultimately tore out the original driveline in my old Spartan, filled in the hole, and drilled a new one 5/16" up from the keel and remounted all the hardware.

The second thing you can do is driving style alone. Roll into the throttle on that boat easy, don't smash it down. That will help stop the chine walking from starting. Also, if it starts walking, you can add a little steering input to settle it down.