90's 2 stroke upgrade from 4 to 5hp?

[Wee Hooker]

A search here has left me cold with 2 stroke conversion info so I'll ask the experts. Just found another nice Tohatsu (with Mariner label) 4hp to keep my 5hp Tohatsu company.
I also have a spare carb from another 5hp Tohatsu. I'm thinking a simple carb swap on the 4hp will boost it to 5hp but am unsure if I'm missing anything.
So can I turn the 94', s-stroke 4hp to a 5hp with just the carb upgrade?
Thanks in advance

 

[pvanv]

Re: 90's 2 stroke upgrade from 4 to 5hp?

Tohatsu didn't market a 4-hp 2-stroke in the US, so you may have a Merc/Mariner-labeled 5-hp Tohatsu powerhead. Whether it has a detuned (smaller carb) setup? Maybe. If you do a close inspection/comparison of the carbs on the Mariner 4 and the Tohatsu 5, you may find the answer to your question.

 

[TOHATSU GURU]

Re: 90's 2 stroke upgrade from 4 to 5hp?

Yes

 

[Wee Hooker]

Re: 90's 2 stroke upgrade from 4 to 5hp?

Carbs look physicly the same on the 4 mariner and 5 nissan. I'm thinking it's juat jet size.

I think I'm just going to try it and see if I get the increase.

 

[TOHATSU GURU]

Re: 90's 2 stroke upgrade from 4 to 5hp?

Pilot jet and the adjustment screw are different. The carb body is the same.