Logo
FULL SITE MENU

Convert a Tohatsu 4HP to 6HP

"Robert, depending on the year

"Robert, depending on the year, it looks like you may just need to "re-jet" the carb. If that is all that is required, then well worth it (along with the appropriate carb adjustments). Otherwise, if it requires a new carb (200 bucks or more) then it is probably not worth it.

The on boat performace difference between a 4 and 6 horse would be minimal at best...

I am however using a Merc service manual to determine this - however, since the mid 1990's the little Mercs have been built by Nissan/Tohatsu. In fact the only difference is the colour and decals."
 
It's a 2000 model Nissan.

It's a 2000 model Nissan. I checked an on line parts catalog and although they listed several different carb's they were the same part numbers for both the 4HP and 6HP motors.
 
"Robert, I suspect that the &#

"Robert, I suspect that the "different" carbs are just the same carb with different jets. That was certainly the indication I got from Merc, with the manual listing 1 carb and the the different jets required for the 4, 5, and 6 horsepower motors - along with the settings for each..."
 
"Robert, was just taking a loo

"Robert, was just taking a look at the 2000 model specs - something you should check out. I am seeing a different cam shaft for the 4 as compared with the 5 and the 6 horse.

Not just a different part number, but actually different dimensions on the lobes...."
 
"All the parts are the same on

"All the parts are the same on the 4, 5 and 6 except for the carb itself. The carb has to be replaced( each size does have a different part number ) as the air mixture jets are fixed for each carb and cannot be replaced. The jets that can be replaced are for fuel flow only."
 
Back
Top