Tohatsu 2.5 and 3.5 2 stroke difference.

[greeny]

I'm just looking to order a new carb for my tohatsu 3.5 2 stroke after a myriad of minor problems with it. When I look at the Tohatsu manual, it looks as though the carb is the same for the 2.5 and the 3.5. Seems wrong to me. I would at least expect different jet sizes on the larger engine or is the difference just the needle position on the slide? Next question is, before I order, is there a power upgrade that could be achieved by fitting a different, larger carb. as on some other engines?

 

[Sea Change]

They're the same, but there's is a washer with a slot in it that restricts the power to 2.5hp. That's literally the difference.

 

[dancrane]

Weird. Is that just the difference between the two engines' carburettors, or the whole difference between the two engines?

Why would anybody have bought the 3.5, if they could buy a 2.5 (or did not it cost less? ) and move the washer to upgrade it?

 

[Mark-1]

They're the same, but there's is a washer with a slot in it that restricts the power to 2.5hp. That's literally the difference.

Wow, you're not far wrong.


Best small outboard engine Tohatsu 2.5 (De-Restricted)

 

[Sea Change]

Weird. Is that just the difference between the two engines' carburettors, or the whole difference between the two engines?

Why would anybody have bought the 3.5, if they could buy a 2.5 (or did not it cost less? ) and move the washer to upgrade it?

The one sold as a 3.5hp also has neutral gear.

 

[greeny]

Ok thanks for that info. Now I can happily order the carb. OR is there an upgrade I can do by ordering a different carb. Sounds like 3.5 will be as far as it will go though.

 

[Sea Change]

Ok thanks for that info. Now I can happily order the carb. OR is there an upgrade I can do by ordering a different carb. Sounds like 3.5 will be as far as it will go though.

AFAIK the next model up (4hp) is a different beast, with F-N-R and twist throttle. Weight jumps up to about 19kg too. And it's basically the same engine as the 5hp

 

[John_P]

The plastic face plate on the 3.5hp has a longer slot to allow a longer travel of the throttle control arm which in turn allows higher revs which give the higher output, its an easy job with a small cutter to modify the face plate of the 2.5hp to increase the travel of the throttle arm.

 

[greeny]

OK thanks everyone. Looks like the 3.5 carb then. I'll order it tomorrow.

 

[benny10210]

I'm just looking to order a new carb for my tohatsu 3.5 2 stroke after a myriad of minor problems with it. When I look at the Tohatsu manual, it looks as though the carb is the same for the 2.5 and the 3.5. Seems wrong to me. I would at least expect different jet sizes on the larger engine or is the difference just the needle position on the slide? Next question is, before I order, is there a power upgrade that could be achieved by fitting a different, larger carb. as on some other engines?

Hi I have the same outboard and it's the same carburetor as my Mercury 3.3hp outboard. Plus the same coil and coil under the fly wheel. Mad !!! No upgrade is available. Kenneth

 

[Geoff Wode]

I had a 2.5 Mariner (no gears) and fitted the Tohatsu 3.5 carb and modified the faceplate.
Light and went like stink for an engine that size.

 

[madabouttheboat]

I have a question thats relevant to this gathering. I have always wondered why the Tohatsu version of said engine was marked up as 3.5hp, while the Mercury/Mariner versions were called 3.3hp. Does anyone know?