Outboard Jet cavitating too much

[Golfmann]

Hi
I have a 16ft Jon boat with a 60hp outboard jet with a aluminum wing when I go to full throttle the boat starts to
cavitate if I slow down the boat won't plane out also when i do get to full speed and make a turn the boat cavitates
and shimmies excessively.(I do expect the some sliding) Wondering if someone has delt with this problem. I have
heard of the Smart Tab but I run and fish in shallow rivers and don't want anything hanging below the bottom of the
Boat. Any help would be appreciated

 

[NYBo]

Re: Outboard Jet cavitating too much

Sounds like the motor is too high on the transom.

Smart Tabs don't hang below the hull.

 

[Golfmann]

Re: Outboard Jet cavitating too much

Hi
The Motor is mounted correctly and I thought that the smart tabs hung down somthing like 25 degrees when not moving so
floating down a river theirs a good chance I would hit them

 

[JB]

Re: Outboard Jet cavitating too much

Since you have the answers, why ask?

 

[Mi duckdown]

Re: Outboard Jet cavitating too much

Pics of your set up. And what is aluminum WING?

 

[Frank Acampora]

Re: Outboard Jet cavitating too much

If your intake is higher than the smart tabs would hang down, then there's your answer. Cavitation on a jet drive is always a function of either the incorrect impeller or air ingestion. If the intake is too high you will ingest air, just like a prop will ventilate.

You need to go over to the outboard forum of your brand. Know the full throttle RPM and know the impeller so they can make recommendations.

 

[UncleWillie]

Re: Outboard Jet cavitating too much

Let's not confuse Cavitation with Ventilation.

Assuming you are Ventilating (Sucking Air), the Anti-Ventilation (AV) Plate is too high.
How fast is Full Throttle?
60hp on a John boat would likely require the AV plate to be right at, to an inch below, the keel to keep it in the water.

 

[H20Rat]

Re: Outboard Jet cavitating too much

not sure on outboard jets, but I'm very familiar with pwc and inboard get drives. Although the depth of your intake is most likely the cause, there are a couple other reasons that it could be cavitating. As the previous post mentioned, air ingestion is one way, but that air doesn't have to come from the intake. If there is a bad seal its not impossible that is where the air is coming in. (some seadoo's were famous for this, the seal on the shaft could leak air while underway.) Also, if the fit between the impeller and housing is bad, it will appear like cavitation. (not sure if outboard jets have wear rings or anything similar)

 

[Mi duckdown]

Re: Outboard Jet cavitating too much

Running outboard jets on 16' jon, is a matter of 1/8 to 1/4 to 1" increments in height to the transom. also weight transfer in the boat.
Running a console or tiller??
Ballast for or aft can be Good or Bad.
You DO NOT Want smart tabs.
Pics Dude.