Prop blowout

[teecro]

Maybe a splash plate on the bottom of the transom would cure that.

Not sure what if anything I'll do at this time.... While the water is boiling around the motor I don't see it causing any real harm at this point. I really want to see what the speed is now with the V bracket removed....

[teecro]

Ok so we got out for a couple hours Friday and here is where I'm at now. Boat is running 16.8 to 17.2 MPH at WOT which according to the tach is at best 5,200 RPM.... Now I'm really starting to think that the prop is not ideally sized for this boat... According to Mercury WOT should be 5,800 RPM and I should be running in the mid 20's... As it now stands I'm running a 3 blade Black Max 14" x 11 Pitch prop so I'm going to consider looking into a prop with less pitch such as a another Black Max 14" x 10 Pitch or 4 blade Spitfire in 13.8" x 10 Pitch....

On a side note I thought that perhaps there was too much slack in the throttle cable and while there is indeed some slack in both the cable and linkage I don't see any real means of adjustment.

[Tlowry]

Use this link;

http://www.go-fast.com/Prop_Slip_Calculator.htm

Enter all the parameters you have which will require the lower unit gear ratio. Once you have that, you can fiddle with the pitch to get the 5800 that will give the actual speed fairly accurate. If you can't get the pitch available, you can have a prop shop re-pitch the one you have.

There should be a threaded barrel on the cable where it attaches to the motor and a WOT indicator mark on the throttle cam.

[teecro]

... There should be a threaded barrel on the cable where it attaches to the motor and a WOT indicator mark on the throttle cam.

Guess that I should have tried a little harder; I did see a threaded barrel devise on the motor and thought that it should provide some adjustability.... Now I've got to wait a month before taking another crack at it....