[Guest]

I replaced my old 30 hp, 2-stroke Evinreude with a new Honda 30hp, 4 stroke. I used these motors on the same 14' Lund Laker. The old Evinrude clearly had more high end speed. I have tried three new pitched props and while top end speed is better nowthan with the original prop, it is still quite a bit slower than my old Evinrude.I love the Honda for a ot of reasons but speed is not one of them. Any ideas what wrong?

 

[Delw]

Those honda fourstrokes are some fast rpm engines, Ive worked on a few those when working for a dealer in the valley and was very impressed.. They are a little slower on the hole shot but usually faster on the max speed.

one thing before you take it in is check and make sure you have the right prop for the max rpm your allowed to turn, Ive noticed they dont preform with the same pitch props as thier 2 stroke conterparts..

While on plane get an rpm reading at WOT and if you can note the MPH

I think you will find once you get it set-up you will like the fourstroke better than the 2 stroke.

if your at wide open throttle now and your RPM is correct you might need a tune up or new plugs at the least.

When you change the oil DONT over fill it or you will bend rods. We had a guy put 5 quarts to many in one of those and he got lucky..
They only hold about a quart and a half of oil(crankcase oil)

Also on any marine engine Timming is a major factor in speed, not so much in the 4 strokes but very much in the 2 strokes,

Delw

 

[nudepygmy]

4 strokes are not going to give you as much top end speed as a two stroke of the same horsepower. It is just because it is a 4 stroke. With a 4 stroke you only get power to the prop every other stroke. With a 2 stroke you get power to the prop every stroke (I hope I explained that right, if not someone with more knowledge of motors help me out). So 2 strokes get higher rpms. 4 strokes are also heavier. Short of trying out different props there isn't much you can do. That is just one of the downsides of 4 strokes.