Nissan/Tohatsu 4hp to 6hp carb replacement

[dmede]

I have a 2002 4hp 4 stroke Nissan outboard. I want to convert to 6hp. I understand from reading this forum that all I need to do is replace the original carb with the 6hp carb. Is that really it? There is no difference in cam lobes or piston dimensions?

Is the carb linked below the correct one for my year and model Nissan?
http://www.internetoutboards.com/partdetail.asp?id=354

My engine-
Model#: NSF4A2D
Carb#: 3H9CQD7

Thanks,

Dave

 

[Sea Rider]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

All 4 strokes 4.5.6 HP engines have 123 cc, instead of changing complete carb, look in spare parts catalogue and change for 6 HP slow jet, main jet could be same for all 3 models. Ask Nissan or Tohatsu before buying a 6 HP carb.

Happy Boating

 

[pvanv]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

Actually, you need the carb. Bigger venturi. And yes, that makes it 6 hp.

 

[dmede]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

Well, I ordered, received and installed the new carb. I haven't had it on the water to check performance increase yet but I can tell just from running it that it does indeed up the power a bit. very easy swap.

 

[aul55555]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

I have a 4hp and have been wondering if I go to 6hp will this give me more speed or power? Would I have to change the prop to gain advantages. I also would like to change to a external fuel tank.

 

[TOHATSU GURU]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

I have a 4hp and have been wondering if I go to 6hp will this give me more speed or power? Would I have to change the prop to gain advantages. I also would like to change to a external fuel tank.

It's two more hp so the short answer is yes. The second question is probably no and if you want to put an external tank on it you have my permission....For whatever that is worth

 

[aul55555]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

Thank you for the help. I guess my real question should have been how does the extra horsepowe give me extra speed? I can see power but, if all things remain the same, except the carberator. what am I missing?

 

[TOHATSU GURU]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

In this case the engine revs higher which spins the prop faster.

 

[petukingdom]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

Hi Tohatsu Guru,sorry for my bad english.Can i increase my Tohatsu 4hp to a 6 hp with just carb replace.I need bit more power to get my 11ft inflatable on planning with me and my wife.If so how much will cost that carb with shipping to Bulgaria(i am from Bulgaria)
Thanks in advance

Petyo

 

[TOHATSU GURU]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

Yes...International shipping should not run more than $50.00. Any dealer can provide the part. Also, any dealer in Europe can provide the part.

 

[petukingdom]

Re: Nissan/Tohatsu 4hp to 6hp carb replacement

Thanks