Nissan 25 hp increase to 30 hp restrictor plate?

[mkwillert]

I have a 2005 Nissan 25hp 2 stroke and was told I could increase it to 30hp by removing a restrictor plate. Do I need to do anything else? What do I need to do to make all this happen? Is this safe for the motor? Thanks!

 

[TOHATSU GURU]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

Remove the carb. Throw away the gasket with the slit in it and put on the 30 hp gasket. That's all you have to do and it will not hurt anything.

 

[mkwillert]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

Is the 30 hp gasket something I need to buy or is it on there already there with the other? Thanks.

 

[TOHATSU GURU]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

Actually...it might be there. I have seen it on some. Sometimes they just have the 25 gasket in place, but all you have to do is scribe a circle in it and trim out the circle.

 

[mkwillert]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

Where might I get this gasket since I dont need the the whole carb kit. How much should I expect to pay so I have an idea. Thanks.

 

[TOHATSU GURU]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

Any Nissan or Tohatsu dealer...or just reuse the one on there already.

 

[mkwillert]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

I did not have the correct tools to cut the one thats on there and I'm afraid I ruined it. It seems like it's rubber coated metal. I'll give the local dealer a call. Thanks Elvin. You've been a big help.

 

[TOHATSU GURU]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

It's just a gasket...I think you are talking about the reed plate assy. The gasket you need to change is the first gasket after the carb. It has a slit in it. Take a razor blade and make it a round hole with the same diameter as the slit.

 

[mkwillert]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

No, it's rubber coated metal right where you said.

 

[TOHATSU GURU]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

It's not supposed to be, but...Is this engine less than six months old?

 

[mkwillert]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

I bought it a month ago, it was made in 2004. Dealer says nissan is backordered on these as well. Oh well.

 

[BassNBob]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

I also have a Nissan 25 electric start, can it be modified the same way if its a 2000 year model.

 

[TOHATSU GURU]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

yes

 

[Papafrankc]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

Tohatsu Guru,

Thanks for the info. It sounds pretty straightforward. I wanted to do the same thing so I noticed that the jets between the 25hp & the 30hp are different so I ordered the jets for the 30hp. I was going to install them but maybe I don't have to if it's just the gasket that makes the difference? If it is just the gasket, then I wonder why they have diffferent jets?

Thanks,
Papafrankc

 

[TOHATSU GURU]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

The jets are the same. Whomever told you they were different doesn't have a clue.

 

[Papafrankc]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

Thanks for the quick reply. I will sure try the gasket modification as it seems the easiest to do.

Here's some info on why I thought there were different jets for the 25 and the 30.

I went to an authorized Nissan service mechanic and we went through the parts catalog together, for the NSF25A and the NSF30A. They're both listed in the same catalog. Here's a link to the parts catalog that I found on the web:

http://www.nissan-outboard-parts.co...atalog NSF25A-30A (2002) - (002N21050-1).pdf


All of the carburetor parts are the same part numbers...except for the following 4 items: (These are the ones for the 30hp)
Page 10 of the catalog:
3R0-03252-0 - Main Nozzle - 1 per carb
3S9-03275-0 - Main Jet #100 - 1 per carb
3R0-03255-0 - Slow Jet #52 - 1 per carb
Page 12 of the catalog:
3R0-03312-0 - Link Rod - 1 per carb

He also suggested I replace the gaskets since I would be dismantling the carbs.
The gasket is listed as the same for both the 25 & the 30
3R3-03293-0

Thanks again for your reply.
Papafrankc

 

[Papafrankc]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

I listed the wrong gasket part nbr...sorry

The gasket they recommended is actually the o-ring for the float chamber - p/n 3R3-03222-0 (page 10 of the parts list).

Question: the gasket that you have been referring to...is it the one on page 7 - p/n 3S8-02011-0 ? It looks like there are 2 of them....one on each side of an insulator plate. They seem to be the same part nbr for both the 25hp and the 30hp. And I don't see any "slit" that has been referred to?

I'm wondering...are we talking about the same engines? The one I have is a 4-stroke Nissan 25hp - NSF25A.

Thanks

 

[TOHATSU GURU]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

No, we were not talking about the same engine. You have a four-stroke so none of what I have stated would apply. Go through the parts book from beginning to end and whatever the part differences are.....Change them out.

 

[HJFF1969]

Re: Nissan 25 hp increase to 30 hp restrictor plate?

No, we were not talking about the same engine. You have a four-stroke so none of what I have stated would apply. Go through the parts book from beginning to end and whatever the part differences are.....Change them out.

Ahhh, can this be the trouth?

Papafrankc, did you try to replace the parts mentioned above?