6 HP; 2 or 4 stroke?

[jspringator]

I have a 12 foot porta bote and my 3 1/2 hp Tohatsu, although an excellent motor, is too slow for that boat with 2 adults and a 6 year old. The new 4 strokes cost around $1,200. I have found a left over 2005 Mercury (read Tohatsu) 5 hp on e-bay that is about 10 pounds lighter than the 4 stroke, and can be carried in any position without an oil mess. Is there any advantage, other than environmental, of a 4 stroke over a 2 stroke? My 2 stroke Tohatsu is the best starting and running small motor I have ever seen. I just need a little more power.

 

[kenmyfam]

Re: 6 HP; 2 or 4 stroke?

Small boat with small outboard I would go with the 2 stroke for the weight advantage alone. You will also get that great smell of 2 stroke when you fire it up !!!!

 

[JRJ]

Re: 6 HP; 2 or 4 stroke?

The smell and the racket is what I dislike about 2strokes. I guess the weight boils down to just how big a boy are you? Bet you can carry a 6hp with one hand regardless of strokes. You'll have fun with whatever you get.

 

[JB]

Re: 6 HP; 2 or 4 stroke?

For your application the best possible outboard would be a 1980s JohnnyRude 6hp. Light, smooth, fairly quiet. It would take many years for the economy of a 4 stroke to pay for itself.

Only risk is that you may find yourself in a place where carbed 2 strokes are banned.

In that case I would be inclined toward 6-8hp 4 stroke twins. Kinda heavy at just under or over 100lb. I think Tohatsu makes most of the brands on the market except for Honda.

 

[Joey One]

Re: 6 HP; 2 or 4 stroke?

Many of the newer 4-strokes were made by Tohatsu.
These do not have the bisquit type vibration dampers; and with the single cylinder,
they vibrate more than the 2 cylinder 2stroke 6 HP. I know; Ibought a 6 HP Nissan made by Tohatsu and quickly sold it at a loss.

 

[kenmyfam]

Re: 6 HP; 2 or 4 stroke?

Another 2 cents from me....
The weight advantage is not for carrying the motor to the boat but jspringator is looking for performance increase. More weight less speed.
The Johnson / Evinrude 6hp is a fine motor and reliable with it.

 

[jspringator]

Re: 6 HP; 2 or 4 stroke?

What year Johnson Evinrude 6? When did electronic ignition begin?

 

[steelespike]

Re: 6 HP; 2 or 4 stroke?

You may want to check your speed with the 3.5.If it is 6 to 8 mph you.re
at the high end of displacement speed. if the 6 can't plane the boat your
increase may be marginal with about double the fuel consumption.Granted
only about 1/3 gal per hour to about 2/3 gph.

 

[kenmyfam]

Re: 6 HP; 2 or 4 stroke?

What is the max hp rating for your boat ???? You may want to go with that. If it is more than the 6hp mentioned so far stick with the Evinrude / Johnson and go with a 8 or 9.9hp if your boat will allow it.

 

[jspringator]

Re: 6 HP; 2 or 4 stroke?

6 HP and 55 pounds. I am sure a 6 will plane it. I understand a displacement hull's speed is limited by its length. You can only go so fast and the hull begins to deform. Then you back off the throttle. If an 8 hp 2 cyclinder weighs less than 56 pounds, then it would work.

 

[steelespike]

Re: 6 HP; 2 or 4 stroke?

You can force a displacement hull to plane but they usually don't like it and handle poorly and don't move efficiently.
A long slender hull moves efficiently at displacement speeds. While a hull might deform when pressed beyond displacement speeds the main concern is inefficient operation and poor handling.
You can operate a Jon boat at displacement speeds but not efficiently especially when compared to a true displacement hull.
In fact a Jon is an example of how not to build an efficient displacement hull.

 

[jspringator]

Re: 6 HP; 2 or 4 stroke?

This

http://www.porta-bote.com/performance.html

is what I'm going to use it on.

 

[hitace]

Re: 6 HP; 2 or 4 stroke?

heres a vid that talks about the pros and cons of both 2 and 4 stroke its not bias in anyway like the etec videos

http://www.youtube.com/watch?v=viWhxvo6DLk

http://www.youtube.com/watch?v=viWhxvo6DLk

http://www.youtube.com/watch?v=LuCUmQ9FxMU&mode=related&search=

 

[jspringator]

Re: 6 HP; 2 or 4 stroke?

This one

http://cgi.ebay.com/ebaymotors/ws/e...RK:MEWA:IT&viewitem=&item=150129963453&rd=1,1

is a nice newer 8, but I don't know the weight. Does it weigh less than 57 lbs? I am sure it is a sweet runner, being a 2 cylinder, but I am guessing 70 pounds.

This one

http://cgi.ebay.com/ebaymotors/ws/e...RK:MEWA:IT&viewitem=&item=320125058461&rd=1,1

is a nice old 6, but he doesn't know the year, or whether it has solid state ignition. Is this one too old? Can you convert to solid state? Should I keep looking?

 

[jspringator]

Re: 6 HP; 2 or 4 stroke?

That 6 is a 1973. Is that too old?