Nissan 25HP carb gasket

[BassNBob]

I bought a 2000 Nissan (NS25C3) in July and decided to check and clean the carb. While doing so I noticed that there wasn't a gasket between the carb and the inlet reed valve. My question is can I buy gasket material from a auto parts store or should I go tho the Nissan dealer and order the gasket. Also what type material is the gasket made and should I convert this 25 to a 30 while I replace the gasket. If I make the gasket, should it be the size of the opening in the carb or the size of the opening in the restricter plate?

 

[TOHATSU GURU]

Re: Nissan 25HP carb gasket

The gasket(s) is available from any Nissan or Tohatsu dealer. I don't know the chemical formulation of that gasket's material(30), but they don't look special. The 25 hp gasket is special and you can't duplicate it. Without a correct gasket as a template you do not want to carve one out yourself.

 

[BassNBob]

Re: Nissan 25HP carb gasket

Bought a gasket for my 25 form a dealer, installed it and now want to know how many turns should the adjustment screw be backed out once it is all the way tighten? Another question is what is the an average speed for a 2000 Nissan 25 HP once it is running again?

 

[Sea Rider]

Re: Nissan 25HP carb gasket

should I convert this 25 to a 30 while I replace the gasket.

Was the carb gasket purchased, a metal one (restrictor)
What boat do you currently use, type/how many feet
The procedure to tune 2 strokes engine single carbed is :

http://forums.iboats.com/showthread.php?t=283488

The average max speed will depend on the boat's hull type, propeller used, total boat weight, wind and sea conditions.

Happy Boating

 

[BassNBob]

Re: Nissan 25HP carb gasket

Thanks Sea Rider, in response to your question. The carb gasket was purchased from a Nissan dealer, Pt.# 346-02011-0, and I removed the metal restrictor plate and replaced with the new gasket.

Now I will adjust my carb. Thanks

I have a 14' alum. boat made by Ultra Jon slight V bottom, a new 9.9 X 13" alum prop, the boat was converted from a jon to a bass boat. Added 3/4" P/W for a front deck and the same at the rear. I'm runnng around 5010 to 5070 RPMs WOT.

Also, is the idle adjustment screw on top or on the side so I can set the recommended RPMs.

It looks like from the explosion view of a Nissan Carb that item 4-1-20 is the adjustment screw and item 4-1-18 is the stop screw.

 

[Sea Rider]

Re: Nissan 25HP carb gasket

Thanks Sea Rider, in response to your question. The carb gasket was purchased from a Nissan dealer, Pt.# 346-02011-0, and I removed the metal restrictor plate and replaced with the new gasket.

Now I will adjust my carb. Thanks

I have a 14' alum. boat made by Ultra Jon slight V bottom, a new 9.9 X 13" alum prop, the boat was converted from a jon to a bass boat. Added 3/4" P/W for a front deck and the same at the rear. I'm runnng around 5010 to 5070 RPMs WOT.

Also, is the idle adjustment screw on top or on the side so I can set the recommended RPMs.

It looks like from the explosion view of a Nissan Carb that item 4-1-20 is the adjustment screw and item 4-1-18 is the stop screw.

Hello BassNBob, 3 Issues:

1-The air/gas screw is generally on a horizontal position at side of carb, the idle screw is generally at a vertical position, on top of a small pawl, move throttle and see at which screw the throttle pawl rests at, that's the idle screw. Needs to be adjusted to 1000 rpm in neutral or 900 at gear.

2-Your stated wot is a bit low, at wot you should be between 5k and 6 k, near 5.5 would be ideal, with same diam prop go 2 down pitch sizes, can gain + 400 to 500 higher rpm at wot.

3-If needed more power to plane your boat faster with weight you can update to 30 HP, having now the correct gasket without restrictor you are just 50% to 30 HP update. Forget about inssurance as you will still be using a 25 HP cowl. If interested follow complete procedure, if any issue not clear just ask: See if the atached pics on thread matches your engine, if so, proceed, you have green flag!

http://rib.net/forum/showthread.php?t=25933

Will have the extra 5 HP at the end of the throttle as the carb will be reaching top 25? timming mark & 180? butterfly position. If converting to 30 HP don't exceed max top 5,850 rpms at wot.

Happy Boating