nissan 25 four stroke to 30 hp?

[kawarider]

Is there a way to bump the 25 to a 30 they are the exact same motor according to the specs.

 

[TOHATSU GURU]

Re: nissan 25 four stroke to 30 hp?

A couple of link rods and three new carbs and you would have the thirty.

 

[HJFF1969]

Re: nissan 25 four stroke to 30 hp?

A couple of link rods and three new carbs and you would have the thirty.

kawarider, did you buy new carbs?

 

[kawarider]

Re: nissan 25 four stroke to 30 hp?

No had some problems with gas in oil that my dealer couldn't fix.Nissan replaced my 06 carb.motor with a new 09 fuel injected motor.So i have a silver gray cover with a fuel injected motor .Runs better than the carb model.I mainly use during duck season in cold weather so big difference in starting an idle.My next motor will be the 40 tldi series for more power.Thanks

 

[kawarider]

Re: nissan 25 four stroke to 30 hp?

What is the difference in the fuel injected motor?Could you just change the ECM and make it a 30HP??

 

[pvanv]

Re: nissan 25 four stroke to 30 hp?

If you have an injected 25, the 3AC-06401-1 ECU for the 30 will work. But I doubt you want to spend almost $1,000 for it.

 

[garbuster_0285]

Re: nissan 25 four stroke to 30 hp?

A couple of link rods and three new carbs and you would have the thirty.

can you just change out the nozzle and jets on your 25hp carbs?

 

[HJFF1969]

Re: nissan 25 four stroke to 30 hp?

can you just change out the nozzle and jets on your 25hp carbs?

You must consider that TOHATSU GURU is a Tohatsu dealer, he sells......carbs and if he has to other things like small jets
"A couple of link rods and three new carbs and you would have the thirty."

Ehh, if you buy 3 new carbs you don?t need to buy the link-rods because they are mounted inside the carbs.
TOHATSU GURU also says that people with big brains can make the 25-30 hp conversion cheaper, you just replace some things.
There is a thread about this conversation somewhere.

EDIT// Here it is: http://forums.iboats.com/showthread.php?t=238757

There is one person that have tried this but i?ve haven?t heard the result from him yet

 

[pvanv]

Re: nissan 25 four stroke to 30 hp?

kawarider's question was about how to convert a fuel injected 25 to a thirty. The difference is the ECU.

Why bash TG over a question that he wasn't asked?

 

[HJFF1969]

Re: nissan 25 four stroke to 30 hp?

kawarider's question was about how to convert a fuel injected 25 to a thirty. The difference is the ECU.

Why bash TG over a question that he wasn't asked?

Please read the whole thread again.

 

[garbuster_0285]

Re: nissan 25 four stroke to 30 hp?

You must consider that TOHATSU GURU is a Tohatsu dealer, he sells......carbs and if he has to other things like small jets
"A couple of link rods and three new carbs and you would have the thirty."

Ehh, if you buy 3 new carbs you don?t need to buy the link-rods because they are mounted inside the carbs.
TOHATSU GURU also says that people with big brains can make the 25-30 hp conversion cheaper, you just replace some things.
There is a thread about this conversation somewhere.

EDIT// Here it is: http://forums.iboats.com/showthread.php?t=238757

There is one person that have tried this but i?ve haven?t heard the result from him yet

Thanks. I am new to the site. every nissan dealer I called wouldnt give me a direct answer. One guy told me I could but there arent any nissan dealers that he knew of that would do it because of EPA standards. Thought I might get a second opinion.

 

[TGuy]

Re: nissan 25 four stroke to 30 hp?

yeah, a lot of dealers won't do mod's any more due to EPA regulations that make it illegal to change the certified emissions of an outboard. And upping the h.p. would certainly change the certified emissions. If a dealer got caught doing it there would be hefty fines to pay. Even if a consumer did it and got caught there would be hefty fines to pay. But then again, how many times have you seen the EPA police out on the water testing the emissions of the local boaters to see who modifiied their motor But from a dealer standpoint, I can see why they wouldn't want to risk their business on doing it.

 

[garbuster_0285]

Re: nissan 25 four stroke to 30 hp?

I know that you dealer guys wont touch it but I have some basic mechanic skills. After I put the nozzles, jets, and link rod am I going to make any adjustments or is it just slap the parts in the carb and go. All I see in my repair guide is the speed adjustment.

 

[HJFF1969]

Re: nissan 25 four stroke to 30 hp?

The one i have spoked to said "it liked the new jets" but he hasnt tried it in the sea yet, we both had some problems with starting the engines without priming with the throttle a few times, he said that it seemed easier to start with the new parts.
He did not make any adjustments that i know of.

To me it is a strange way to restrict an engine, there should be a risk that the engine is going warm with the smaller jets because lean gas/air mixture, but i guess Tohatsu/Nissan knows best

Please tell us the result if you do the modification.

 

[garbuster_0285]

Re: nissan 25 four stroke to 30 hp?

Well now I need a serial number for a 2004 NSF30A. They want it to order the parts.

 

[garbuster_0285]

Re: nissan 25 four stroke to 30 hp?

Well I put new jets, nozzle,and link rods. I didnt touch any adjustments and It cranked up great, but when I put it on the water it wouldnt run as fast as it did when it was a 25 any one got anything?

 

[HJFF1969]

Re: nissan 25 four stroke to 30 hp?

Well I put new jets, nozzle,and link rods. I didnt touch any adjustments and It cranked up great, but when I put it on the water it wouldnt run as fast as it did when it was a 25 any one got anything?

Hmm, not fun!

How did it run on idle and middle throttle?

Since you have replaced the parts that make it 30hp what else can make a difference, ignition timing? valve timing???

I have thought that restricting an engine with just fuel-jets is a strange way to do it, it should also have more air.
The "25hp" should run lean and very hot with smaller jets?

The GURU himself says that it?s pretty easy and cheap and that you don?t need to replace the carb-housing, so how make it breath easier?

 

[John_S]

Re: nissan 25 four stroke to 30 hp?

Not familiar with this motor, but doesn't the link rod tie into the ignition advance? If so, suspect the timing settings are different than the 25hp. Nissan/Tohatsu did something similiar on older 2-strokes.

 

[garbuster_0285]

Re: nissan 25 four stroke to 30 hp?

The motor idiled great. Matter fact when I had the muffs on it I couldnt tell any difference. When I got on the water it acted like I put a prop with to much pitch on it. Does the motor lose torque when made to a 30? just wide open its not winding up alot of RPMs. The dealer wanted 200 plus parts. I didnt have enough money. I bought a repair manual and looked over the carb. There wasnt nothing difficult to replacing the parts so I did it myself. Unlike a cars carb there is no adjustment screw to change fuel and air. The only adjustment is the speed screw(Which I didnt touch). I made sure the floats were in the right spot. Any help would be appreciated. I am unemployed and dont have the money to take it to the dealer. Please help me out.

 

[HJFF1969]

Re: nissan 25 four stroke to 30 hp?

Not familiar with this motor, but doesn't the link rod tie into the ignition advance? If so, suspect the timing settings are different than the 25hp. Nissan/Tohatsu did something similiar on older 2-strokes.

I believe the link-rod is placed inside the carb and acts like an acceleratorpump when accelerating but i?m not sure, whatsoever has it no effect on ignition timing.

The timing settings should be seen in the service manual, anyone got one?