Nissan NS25c maintenance item help

[Helgaiden2]

Hi all,
so its time i do some maintenance on my mini-boat which has a Nissan NS25c outboard (same as Tohatsu NS25b from the same time i believe), which appears to be a late 80s/early 90s model i think. The boat itself is registered as a 1986 model. Last i tested, it still expels water so the impeller is still doing its job, but i've got friends more knowledgeable than I in boating advising i change to be on the safe side (in the time i've owned it, i never changed it though the boat hasn't gotten a whole ton of use either). Here is a picture of the engine (not mine specifically but its this model, though mine appears longer)

So im not sure but cant seem to find the right impeller for my needs. I think this might be the right one though and was wondering if any of y'all can help me out a little bit in finding what i need?
https://www.ebay.com/itm/Outboard-W...054641?hash=item2cb3707cb1:g:-K0AAOSwFe5X1lk8

Another thing when changing the impeller than im not sure i'll need is the lower unit gasket kit that i've also seen while trying to find the right impeller. This came up, but it says its for the NS25c2 which i dont think my engine is:
https://www.ebay.com/itm/For-TOHATS...328208?hash=item1a29da64d0:g:FzMAAOSwWxNauFZk


I discovered the carb also has a torn seal as well and was trying to find a carb rebuild kit without much luck, i keep striking out on that one.

Now up until this point, i haven't really had any issues with it. Just trying to stay ahead of any failure.

So im hoping maybe some of you more knowledgeable than I can point me in the right direction. None of my buddies have outboards, let alone 2-stroke engines so their help can be a bit limited.

At least there is this video that will help me in getting the impeller changed as it seems to be my exact engine too.

https://www.youtube.com/watch?v=HRHVI4W-4cY

Thanks in advance...

oh and here is a pic of the boat

 

[pvanv]

You need

Water pump repair kit. Includes all parts needed to replace water pump.
Fits:
25C2 & 25C3 2-stroke models
30A3 & 30A4 2-stroke models
40C 2-stroke model
Part #: 361873220M
List Price (MSRP): $49.00

Carburetor repair kit. Kit includes gaskets, float & needle valve.
Fits:
25B ~ 25C3 & 30A ~ 30A4 2-stroke models.
Part #: 346871220M
List Price (MSRP): $48.95


Available from any dealer.

 

[Sea Rider]

Yours is a Tohatsu 25C2 or 25C3 model ? can convert it to a 30HP one for peanuts cost if being a 25C3 OB, don't know about the 25C2 ? Paul should know if possible.

Seeing your pic the OB is trimmed slightly down, trim it one hole upwards for cowl and lettering to sit parallel to water level, that way combo will ride much better parallel to water level when on plane, right now as trimmed bow digs in water bit more than it should.

Add new gear oil to the equation...

Congrats nice speed machine, converted to a 30 HP, with adequate OB/transom height and max propped should fly to Mars and beyond...

Happy Boating

 

[Helgaiden2]

You need

Water pump repair kit. Includes all parts needed to replace water pump.
Fits:
25C2 & 25C3 2-stroke models
30A3 & 30A4 2-stroke models
40C 2-stroke model
Part #: 361873220M
List Price (MSRP): $49.00

Carburetor repair kit. Kit includes gaskets, float & needle valve.
Fits:
25B ~ 25C3 & 30A ~ 30A4 2-stroke models.
Part #: 346871220M
List Price (MSRP): $48.95


Available from any dealer.

awesome thank you so much.

Yours is a Tohatsu 25C2 or 25C3 model ? can convert it to a 30HP one for peanuts cost if being a 25C3 OB, don't know about the 25C2 ? Paul should know if possible.

Seeing your pic the OB is trimmed slightly down, trim it one hole upwards for cowl and lettering to sit parallel to water level, that way combo will ride much better parallel to water level when on plane, right now as trimmed bow digs in water bit more than it should.

Add new gear oil to the equation...

Congrats nice speed machine, converted to a 30 HP, with adequate OB/transom height and max propped should fly to Mars and beyond...

Happy Boating

The badge on it just says NS25C, though when i bought this boat it had a twin/2nd boat with a black Tohatsu version of this engine that had the badge NS25B. Neither had any numbers after the letter in that badge though. I've heard of getting a few more HP out of this by removing some plate behind the carb, though i've also heard of people having idling issues after removing it so for the sake of "good running" i never dug any deeper with it. We'll see what happens when i do the carb rebuild though. Just did the gear oil a few months back actually, but it looks like i'll need to redo it which is no biggie since i still have more oil and everything. Thanks for the trim tip, i'll give it a shot!

 

[TOHATSU GURU]

It was just a gasket difference back in those days.

 

[Helgaiden2]

It was just a gasket difference back in those days.

Alrighty cool, thanks. To add to PVANV's post parts suggestions, i wouldnt need a lower unit gasket kit or anything like that would i? or would that be included in the water pump repair kit?

 

[Sea Rider]

Lower unit kit is a separate one from water pump kit, are 2 complete different kits.

Happy Boating

 

[Helgaiden2]

Lower unit kit is a separate one from water pump kit, are 2 complete different kits.

Happy Boating

Ok cool. Would i need to change the lower unit gaskets doing the water pump/impeller servicing? If so, is one of these the right kits?

https://www.amazon.com/Sierra-Intern.../dp/B015E8SG6C

https://www.tohatsu.us/index.php?mai...ucts_id=117588

https://goo.gl/nNMnWd

Appreciate all the help, guys.

 

[pvanv]

No need to change out LU seals to do a water pump. However, if you do want to do the LU seals while apart, order:

346873217M

LOWER UNIT GASKET SET

$31.93

/*uses 2 prop shaft seals-spring side out*/

 

[Sea Rider]

A Nissan M25C whatever 2-3 is it it's same as an upgraded Tohatsu M25C3 or for that matter a M30A4-OB. It's simply a carb gasket swap and correct carb/time advance sync, peanuts cost and straightforward to check sync or even dial them correctly. No idling difference whatsoever if the work is done correctly. Much better if installing a new carb kit if required.

That combo should benefit going for a HP upgrade along a prop maximization if the current prop pitch happens to be a 13 one which in light to medium light boats was found to be over propped to rev inside safe 5200-5800 wot rpm range. Let us know if wanting to go towards that route to explain step by step how it's done. You'll love the conversion once fully done...

Happy Boating

 

[Helgaiden2]

You guys are awesome, thanks.