Real world difference between a 2.5 and 3.5 outboard

[colbyt]

I am in the market for a new small outboard for use on restricted lakes. Some spec reading leads me to believe the the 3.5 models are the same as the 2.5 with better fuel supply. 3.5 is mathematically about 40% more power but I am sure other factors enter into the equation.

I know a lot of you use these small ones as kickers so my question is: what type of real world increase can one expect between a 2.5 and a 3.5 when it is used on a boat that it is never going to plane?

All things except price being equal which would you buy and why?

 

[Mi duckdown]

Re: Real world difference between a 2.5 and 3.5 outboard

What type of boat?

 

[JB]

Re: Real world difference between a 2.5 and 3.5 outboard

I would find a well cared for Johnny JW 3HP or one of its sisters (Evinrude Lightwins) or descendants (up to 4.5HP).That series are the best small outboards ever made. . .much better than current offerings.

 

[ondarvr]

Re: Real world difference between a 2.5 and 3.5 outboard

There is a difference, but it's not huge, if one works for your needs so will the other one. They aren't great motors though.

 

[Chinewalker]

Re: Real world difference between a 2.5 and 3.5 outboard

The difference would most likely be noticed by a 11 year old who suddenly discovers that the little 2.5hp that plained him off last year doesn't plane him off this year... A 3.5hp might gain him another season of being able to plane off...

 

[Silvertip]

Re: Real world difference between a 2.5 and 3.5 outboard

I seem to draw fire for asking questions that are seemingly unrelated to your question, but exactly what type of boat are you attempting to power, what are the HP restrictions, are there speed restrictions, what is the lake size and what sort of performance are you looking for. With none of this information available, either engine may be a mistake. But based on the little information you've presented, 40% more power is rather significant but that number does not tell the full story since the boat you are powering has much to do with expected performance difference. A 420 HP engine has 40% more power than a a 300 HP engine. Do you think that is significant? One needs to look at the type of boat those examples are powering. If the boat is too big for a 2.5, a 3.5 may be barely adequate, but a 5 HP would be better.

 

[colbyt]

Re: Real world difference between a 2.5 and 3.5 outboard

I thought the question would stand by itself with no need for an explanation since I said all other things being equal. I guess I was wrong.

Assume a flat bottom jon, tin boat 14' x 60" beam and the maximum allowed horsepower on the lake is 3.5.