Tohatsu 4hp parts to make it a 6hp?

[edgarwu]

Re: Tohatsu 4hp parts to make it a 6hp?

Thanks Elvin for the input. I input awaiting for an call back from an outboard shop regarding that. Just from the tech specs, prospective the two motors (BF75 and BF100) are identifical; such as the displacement, valve tappet clearance, spark plug gap, etc. The only difference is the full throttle range where the BF100 is 500 rpm higher. That's why I was wondering if there might be some trick to "unlock" the power. As far as my BF75 performance goes, it runs great and starts in a couple of pulls. I just hope to get more out of it when riding in a bit choppy Monterey, CA shoreline.<br /><br />Cheers

 

[richmond331]

Re: Tohatsu 4hp parts to make it a 6hp?

Hi Elvin

I have a 2005 4 stroke 4HP Tohatsu sail drive which I would like to change the carb and make it a 6HP.

I am also wondering if it is possible to convert it from a short shaft into a long shaft to use on my yacht?

I am guessing there are two options, 1 find an old long shaft and put my power head on. 2 order the long shaft parts and put on my short shaft

any info or advice would be much apprieciated

Thanks

 

[TOHATSU GURU]

Re: Tohatsu 4hp parts to make it a 6hp?

Just a carb change to make it a 6 and your right about the two ways to make a short a long. The parts are available from any Nissan, Tohatsu or Mercury dealer....The Mercury labeled parts cost more.

 

[richmond331]

Re: Tohatsu 4hp parts to make it a 6hp?

Hi Elvin, had a look at the link you supplied for shaft extension kits. I have a 4 stroke 4hp Tohatsu short shaft. Is there an extension kit that will convert short shaft to long shaft or is it only long shaft to extra long shaft?

Thanks

 

[TOHATSU GURU]

Re: Tohatsu 4hp parts to make it a 6hp?

http://www.internetoutboards.com/partdetail.asp?id=1022

 

[richmond331]

Re: Tohatsu 4hp parts to make it a 6hp?

Hi Elvin

What is the standard position/turns for the pilot set screw on a 4HP Tohatsu carb?

Thanks

 

[TOHATSU GURU]

Re: Tohatsu 4hp parts to make it a 6hp?

I have no idea as they are set by instrument in Japan. There isn't a reason to to access it for service, but if one did, you would set it back to whatever it was before you tinkered with it.

 

[richmond331]

Re: Tohatsu 4hp parts to make it a 6hp?

Hi Elvin

Pilot set screw was about 1.5 turns, just wanted to make sure as it does not say in my manual

Also can you please tell me what is the triangular shaped piece of metal that sticks out of the leg housing? (Tohatsu 4hp 4 stroke LS) It has two holes in and is about 10cms down from the steering friction adjuster knob.

There is no mention of this in the manual, I thought that the exhaust was through prop and the water was through tel-tale, I can't work out what this does. Any ideas?

 

[TOHATSU GURU]

Re: Tohatsu 4hp parts to make it a 6hp?

That's just the leg exhaust port...I can't think of an outboard that doesn't have one in about the same spot.

 

[PotatoAddict]

Re: Tohatsu 4hp parts to make it a 6hp?

Just a carb change to make it a 6 and your right about the two ways to make a short a long. The parts are available from any Nissan, Tohatsu or Mercury dealer....The Mercury labeled parts cost more.

Hi Elvin. Is changing the carb a pretty simple process? Any special tools needed? Any place I might find some instructions? Thanks!

 

[pvanv]

Re: Tohatsu 4hp parts to make it a 6hp?

Hi Elvin. Is changing the carb a pretty simple process? Any special tools needed? Any place I might find some instructions? Thanks!

Tater,

It would have been much better to start a new thread, instead of reviving a 2 year old one, but... a carb swap on the NSF/MFS 4/5/6 A2/B/C is pretty straightforward. Two 6mm bolts hold it onto the intake. You also need to disconnect the throttle and choke, as well as the fuel line. Ordinary metric hand tools are all you need.

The heads on the carb bolts are 10mm. The inner bolt cannot be turned with a conventional socket while the recoil housing is installed, but it is also setup to be turned with a #2 Phillips screwdriver, then snugged with a 10mm box wrench. If you feel that this procedure is daunting, it would be best to seek the assistance of someone with more experience... a neighbor, friend, or a dealer. There is detail in the Factory service manual, but it assumes that the technician has basic mechanical skills, and some experience.

 

[PotatoAddict]

Re: Tohatsu 4hp parts to make it a 6hp?

Tater,

It would have been much better to start a new thread, instead of reviving a 2 year old one, but... a carb swap on the NSF/MFS 4/5/6 A2/B/C is pretty straightforward. Two 6mm bolts hold it onto the intake. You also need to disconnect the throttle and choke, as well as the fuel line. Ordinary metric hand tools are all you need.

The heads on the carb bolts are 10mm. The inner bolt cannot be turned with a conventional socket while the recoil housing is installed, but it is also setup to be turned with a #2 Phillips screwdriver, then snugged with a 10mm box wrench. If you feel that this procedure is daunting, it would be best to seek the assistance of someone with more experience... a neighbor, friend, or a dealer. There is detail in the Factory service manual, but it assumes that the technician has basic mechanical skills, and some experience.

Thanks (and sorry about the thread)!

 

[Sea Rider]

Will depend entirely on the engine model, small portables are much alike, medium could have some differences on throttle and shifting mechanisms. Powerheads, rest of the engine should be same up to certain HP models, the ones that are not Tohatsu rebadged.

Happy Boating