I own a Sea-Doo SPARK TRIXX 2 UP that I love to ride. It’s incredibly lightweight, has a 90 HP engine, and I can quickly get it up to 50 MPH on relatively flat water. I live in a house with a dock on a canal, off a private marina, and off a river that spills into a very large lake. The canal and marina are posted with no wake zone signs, so I must keep my speed down until I reach the river.
At normal speeds, it has precise steering, but at low speeds, under five mph, it’s almost impossible to keep it going straight. It swerves back and forth from side to side. It’s as if I’m constantly over or understeering, but I’m not. There’s no way I can go three mph in anything approaching a straight line, which makes getting around boats and obstacles tricky. However, it steers perfectly straight with no effort if I take it up to five mph. But at five mph, I’ve got a wake.
So what’s happening here? Do all PWC do this? Is it because it’s so lightweight?
I ain’t a watercraft mechanic, but it sounds like maybe something mechanical is wrong, have you had it looked at? Like maybe a linkage is broke/loose/bent or something, or perhaps the impeller shaft has something wrong with it perhaps(it is jet propelled, yes?).
No, it doesn’t have a prop. The fact that it works perfectly above five mph makes me think it isn’t a mechanical issue. I guess I have to talk to someone who owns one to see if theirs does it too.
This sounds like normal PWC behavior to me. There’s no rudder, so it requires propulsion to steer. Less propulsion means less responsive steering ability. You’ll get used to it eventually, but it will always perform better when its just a little bit faster.
That occurred to me, and at high speed, they are up on the water, so maybe that’s why they are so squirrely at low speed. I just thought someone much more intelligent than me could say they all do that.
I’ve never used one, but it’s my understanding that these things don’t have a rudder, in the normal sense. All they have is a steerable jet outlet. It only steers by pushing water away from the direction you want the back of the thing to go. In that, it’s similar to a rudder, except that it quits working when you aren’t using the throttle. I’ve heard this causes PWC renters to have accidents, because the handlebars don’t work at all without throttle. (While I was writing that, other people already posted most of that.)
Perhaps the answer is to steer at low speeds by short directional blips of the throttle instead of a steady low throttle. It is a boat, after all, so it will keep moving in between steering surges.
It’s normal behaviour. There is little about a PWC hull to give directional stability - no rudder, little or no keel, not much by way of strakes. Add to that - the jet is powerful and even tiny directional inputs at low speed easily overcomes any directional stability the hull may have.
As the speed rises, the hull’s (modest) directional stability becomes more effective, and the PWC becomes more steerable.
Okay, I can see that, but if the jet is pushing straight backward at idle speed (three mph), and the steering is pointing straight forward, what force is pushing it strongly to one side or the other? IOW, what makes it wander left or right if I am steering forward? Remember, at 50 mph it goes straight forward if I am pointing that way.
Wind, waves, current, torque, body lean and weight shift; same as when you’re going fast but you no longer have as much forward inertia, throttle or steering control that you have at higher speeds.
One could as easily say “If I lift an object with one finger, why does it topple?”. The system has barely any stability at all, and you have forces acting on it. Going straight would be an anomaly.
Okay. I’ll test it out tomorrow. For the record, at this time of year, there are no currents, waves, wakes, or wind to deal with in the canal. I will sit as still and squarely as possible and just point it forward at idle speed and see what happens.
.