70 HP Johnson , slow to plane?

Question

Just bought a 96 Stratos 258, and the boat is very slow to plane. It top ends at about 30, at 4600 RPM. Any suggestions?

Answer 1

For every 2 inches pitch you drop your prop , your revs will increase by about 400 rpm. You  should be revving at 5000-5500 top end. That means you need to get a prop that is 2 to 5 inches less pitch than what you have now. ( If you're running a 19" go to a 17" or 15" , or a 14 even, if you can find one.)

Answer 2

too much prop pitch.

Answer 3

Boat planing is basically a combination of speed vs. weight and design of your boat. If you're "slow to plane" be sure that your weight is distributed evenly in the boat and not all at the rear. If this is done, you are probably underpowered. A larger motor on this boat will improve your planing speed as well as top speed. You need the speed of the boat to be able to lift the back of the boat to lower the front. You will gain speed the more you get the boat flat to the water and not "plow" through it.

Also, if your boat is setup with a hydrolic trim, be sure to start with this in the fully down position. This will improve your plane time. Once you have reached top speed, you can adjust your trim more "up" which will lift the front of the boat slightly causing less drag in the water and also increase your speed.

Answer 4

$34 answer is a set of those Doel-fins.  They'll help you get up on a plane quicker and keep you up there at lower revs...  Get them now and when you can change the prop it'll still help you out a lot...  They'll pay for themselves quickly!

Answer 5

get a smaller boat or a bigger outboard