28ft Tahoe

[Milan15]

I have a 28ft Tahoe tritoon with a 115 Mercury max rpm 5900. When I got the boat it was used and had a 13 x 10 pitch prop. It would cavitate pretty bad when turning. Went to a 14 x 11 pitch. It no longer cavitates however I lost top speed by about 10 mph and only can get 4900 rpm. Is there a prop that will fix the cavitation and still give me the top speed?

 

[ThomW]

The cavitation might not be prop related and could be a result of engine mounting height. The old prop you were going faster, bigger wake behind the toons and therefore it cavitated. New prop you are 10 MPH's slower, with smaller wake so no cavitation. can you take a picture of engine mount from the rear so we can see the height?

 

[Milan15]

I can get a pic this evening. However the motor is at its lowest point already.

 

[QBhoy]

What 115 is this ? What age ? Sounds like a small engine for a 28ft perhaps. It would need to be a CT 115 to have any real result on that boat, you’d think.

 

[jbcurt00]

I have a 28ft Tahoe tritoon with a 115 Mercury max rpm 5900. When I got the boat it was used and had a 13 x 10 pitch prop. It would cavitate pretty bad when turning. Went to a 14 x 11 pitch. It no longer cavitates however I lost top speed by about 10 mph and only can get 4900 rpm. Is there a prop that will fix the cavitation and still give me the top speed?

You probably mean ventilation not cavitation. Ventilation is the prop breaking the water surface in a turn.

Cavitation is the bubbles that form and cause damage to the backside of the prop blade's leading edge.

 

[Milan15]

What 115 is this ? What age ? Sounds like a small engine for a 28ft perhaps. It would need to be a CT 115 to have any real result on that boat, you’d think.

It's 2007 Mercury 4 stroke

 

[Milan15]

The cavitation might not be prop related and could be a result of engine mounting height. The old prop you were going faster, bigger wake behind the toons and therefore it cavitated. New prop you are 10 MPH's slower, with smaller wake so no cavitation. can you take a picture of engine mount from the rear so we can see the height?

 

[Milan15]

The cavitation might not be prop related and could be a result of engine mounting height. The old prop you were going faster, bigger wake behind the toons and therefore it cavitated. New prop you are 10 MPH's slower, with smaller wake so no cavitation. can you take a picture of engine mount from the rear so we can see the height?

 

[Milan15]

I have a 2007 Tahoe tritoon Mercury 115 outboard. Is there any way I can find out the original size of propeller it came with?