Jet Drive Outboard Motor Debris

[JohnSz]

Here what the bottom looks like. I would imagine the keel at the bottom would cause some cavitation not suitable for a jet drive, yes?

View attachment 403877View attachment 403876

It could. On our jet boat, it stops a distance in front of where the tunnel starts. It just covers the curved part plus a foot or so.

 

[sailorb12]

It could. On our jet boat, it stops a distance in front of where the tunnel starts. It just covers the curved part plus a foot or so.

 

[Chris1956]

Gee, don't jet drives pull most of the water straight up from the bottom? I would not expect the keel to affect that.

I would expect the keel to affect a prop drive, as the prop pulls water from under the hull.

 

[JohnSz]

Gee, don't jet drives pull most of the water straight up from the bottom? I would not expect the keel to affect that.

I would expect the keel to affect a prop drive, as the prop pulls water from under the hull.

Only when going slow. The forward motion feeds the water it needs. You would burn the motor up if you ran the shoe parallel to the boat bottom. For running, trim is limited to fully tucked in to where the drive shaft is perpendicular, which isn’t much. Most just leave fully tucked in. OutboardJets recommend a slight mod-v hull over flat bottom because it will channel air bubbles away from the center. It’s not guaranteed to be a problem, but the only way to know is to test. Might be able to set motor deeper to alleviate it. But the heel will be more of a risk for impact.