Motor Issues!

I have a 1985 Bass Tracker Pro Guide V16 Aluminum boat with a 20" transom. It currently has a long shaft 35 hp Evinrude with no tilt or trim. My problem is three fold, first is the motor won't push the boat any faster than about 18 mph WOT. Second, I have it set on the last hole (in the bracket) closest to the transom and water splashes inside and won't keep the bow down. I should also add that I installed a Sport SE to help with bow problem. It has been suggested that the motor is to long for the boat even though the cavitation plate is even with the bottom of the boat. I would like to hear comments and or suggestions.

See if both cylinders are firing.

both are firing, I know thats not the problem.

try to raise the prop away from the back of the boat. a tilt and trim will allow you to have the motor tucked under the boat to get the bow up and then you trim the motor up(move the prop away from the boat to get the boat on plane. Try setting the motor in the second or third hole in the bracket that may help

There is a splash plate above the cavitation plate on most of the engines, which one are you talking about? The cav plate is the one closest to the propeller. Also,take a straight edge and place it along the bottom near centerline. Extend it out and take a tape measure from the top of the transom to a point on the straight edge 90 degrees off the bottom(your tape, at the bottom should be several inches away from the metal transom). What is that measurement? Give me a model number of your engine as well. Let's start from there and see if we can help.

Pappy,

The measurement that you wanted is 19", the Evinrude model number is 35753H. Now with everything good and level, it appears that the cavitation plate (closest to the propeller) is about 2" lower than the bottom of the boat.

After ................you raise your engine as previously suggested....see if you can get the hydrofoil off of the boat. While they can help raise the stern to prevent porpoising and get the boat on plane....they also can subtract from your speed.

I've used Smart Tabs and found them a better choice for raising the stern without losing speed and power. After all, anything dragging in the water is a problem. Rich

Raise your motor and lose the hydrofoil like mentioned before. Lose any unneeded weight and move as much weight to the bow as possible. Maybe change the pitch of the prop.
That's about all you can do without going broke.
A 50hp motor would solve your problems.

The guys before me have answered your question perfectly. The number you gave me was a serial number, not a model number but thats okay. Am guessing you have a 20" engine on a 20" (give or take) transom. Boat manufacturers typically take the safe route when manufacturing boats and setting transom heights up on the assembly lines. They will always err on the less is better rather than take a chance on customer and dealer complaints of cavitation in turns, while plaining, etc. from having a transom that is too high. They would end up having to pay warranty claims to cut transoms or take boats back and do it and pay to have the boat returned to the dealer/customer. To add to that if you were to actually measure the different brands of engines you would find that they are almost always different as well. To even add more to that there are drastic differences in where cooling water is picked up so some brands are more sensitive to engine height than others. Bad part about a short transom is the issues you have at this time. Excess spray and less than optimal performance. Try and get your cavitation plate up to at least level with the bottom, measured when the plate is parallel to the bottom of the boat (don't measure when it is all the way trimmed in) or a little above it.

Thanks guys!