nissan 25hp advice

[fishon1213]

My brother has a flatbottom with a late 80's nissan 25hp, he recently ran afoul something on the rock river. When I looked at the motor what I saw was no major external damage other than the prop. When the motor is in reverse it is engaged, neutral it spins freely, forward it will spin freely(ouch!!!). So I am thinking either a new forward gear or clutch dog.
The other thing is he said it wont idle now. Will a bad lower unit cause that?

 

[TOHATSU GURU]

Re: nissan 25hp advice

Internal damage to a lower unit can cause an engine not to run. The increased friction from damage can cause an RPM loss severe enough to prevent the engine from operating.

 

[fishon1213]

Re: nissan 25hp advice

Ebay is very limited on the older nissan motors. Where are some good sources to find parts for these motors?

 

[TOHATSU GURU]

Re: nissan 25hp advice

Any Nissan or Tohatsu dealer.

 

[pvanv]

Re: nissan 25hp advice

Ebay is very limited on the older nissan motors. Where are some good sources to find parts for these motors?

Parts are still available new:

346642151M CLUTCH $54.47
346640101M BEVEL GEAR A (FORWARD) $100.85
346640201M BEVEL GEAR B (PINION) $68.55
346640300M BEVEL GEAR C (REVERSE) $94.80

Worst case would be if you need the entire LU. If so, and you have the 20" length, you would order: 346S873027 LOWER UNIT 25/30 (NEW STYLE) LONG $943.17.

 

[fishon1213]

Re: nissan 25hp advice

Thanks for the advice. I am not sure I want to put that much money into this motor. I guess I have the winter to decide to fix it or start looking for another motor.
Honestly I haven't been to happy with this nissan. I have always had johnnyrudes and may switch back.

 

[pvanv]

Re: nissan 25hp advice

Understood. You can up the hp on those to 30, if you didn't know. Then too, it's still cheaper than the $thousands you would spend on a new $5,000 30 hp motor...

 

[fishon1213]

Re: nissan 25hp advice

I haven't been happy with the nissan because of hard starting, running sluggish, and it uses alot of gas. All of which are probably a carb issue.

The nissan actually is not mine, its on my brothers 16ft johnboat. After checking the plugs I told him to check out the carb. He took it apart and cleaned it but the engine runs no better. I told him he needs to do a COMPLETE carb rebuild and adjust it properly. I was just getting ready to help him with that when he trashed the lower unit. Not his fault though, we fish the rock river and it is treachorous.

Is converting to a 30hp as simple as changing the jets, or is there more involved?

Whats everybodys opinion on these nissan 2strokes?

 

[pvanv]

Re: nissan 25hp advice

Need your exact model/serial to determine what is needed for the HP upgrade. Most models can be done cheaply.