How far is to far? I have a 16 foot stinger with a yamaha 60 two stroke.The dealer had the motor all the way down, therefore making the boat porpoise real bad when trimming the motor up. I had to keep the motor trimmed down to the point that is seemed like it lugged and would only run 28mph. I moved it up one notch and its better, but water is still flowing over the hydrofoils when i’m on plane. Do i keep adjusting it up until there is no water above the hydrofoil when on plane? Will i eventually give up my hole shot making it hard to pull a tube etc? It now runs 31 mph. I do not have a tach on this boat so rpm;s are unknown at this time.
I’ve heard that the cavitation plate should be even with the keel to keep it from porpoise. Not sure if that varies a lot between different make of boat/motor combos though.
Take the foils off and test it. Something isn’t right if plate is 1 inc high and water still runs over it. Side pic of boat and plate might help us help you. The only thing that helps my 1720 kw is extra weight up front. Fins or not it will porpoise at a certain trim angle.
All of the Yamaha published performance reports I’ve read state the motor is on the second hole during sea trials. Try that and see if that don’t fix it. CC is correct, any boat will porpoise if trimmed too high.
GW 232GT Gulfstream
150Yam x 2
“3rd Day”
Gen. Chap.1 Vs.9-13
It doesn’t take much trim for mine. Just try to get more than 2 feet of the bow up and it is hello bucking bronk. Add 150lbs to the bow and she will trim back to the console.
the stingers have the cathedral style hull, and need the motor mounted a little higher than normal
water should be below the cavitation plate
witha 60 2 stroke on a boat that light, you shouldnt need the foil at all
take it off, and raise the motor another hole, and test run it
u should be running faster than 31 with that boat and motor