Cavitation

[hydra22]

I have a 89 22' hydrasport walkaround with a merc 225 mounted on a bracket and I'm having allot of cavitation when on plane and less then 1/2 tank of gas I can only go down 1 more hole on the bracket but my question is that theres a a thru hull ducer mounted even with the transom and 3" to the left of the keel and sticks down about 4" is this in the right spot.Also the cav plate is about 2-3" above keel with 30"of setback from the bracket. By the way this is my first boat.

 

[JB]

Re: Cavitation

HHHMMMM.

The Xducer is too close to the keel. Move it out to at least 8".

I think what you are getting is ventilation, not cavitation, caused by the wake of the Xducer.

 

[hydra22]

Re: Cavitation

Is my motor height about right.I was thinking of dropping it another inch.The prop actually feels like it blowing out of the water and my rpms jump I already switched props

 

[AJ168]

Re: Cavitation

I agree with JB, but it's worth a shot to drop the engine down a bit if it's not too hard before you go moving the transducer.

 

[Texasmark]

Re: Cavitation

Did you say the engine is on a bracket which is 30" behind the transom?

Also I'd get the depthfinder off to the side well away from influencing the prop's water intake. The comment you made about the level of fuel influencing the performance sorta suggests your moving the engine down is the right thing to do.

Over in prop forums (as I recall) there is significant dialogue about the ratio of setback to antivent vs hull location. Dhadley knows if you ding him.

Mark

 

[mikey.himself]

Re: Cavitation

What is a transducer?

 

[JUSTINTIME]

Re: Cavitation

the more set back the motor is from transom the higher you can go
you need to look at the cavitaion/anti-ventilation plate on the motor when at wot to see if it is just in the water
you need the transducer 12" minimum from the lower unit

a transducer is for a depth finder or fish finder, reads depth