89 nissian ns40c running problems

[Zbhsmith]

I have a 89 NS40C I cant get to stay running. I need a carb rebuild kit but I cant find one. and what are the setting for the carb. It seems like its getting to much fuel. I dont know much about them. So any help would be great.

 

[pvanv]

Re: 89 nissian ns40c running problems

You need: Part # 345871223M Carburetor repair kit. Kit includes gaskets, float & needle valve. Fits: 40C 2-stroke model. $52.13, available from any dealer, including me.

I would highly recommend the Factory service manual, Part # 003-21035-1 Covers all 1 & 2 cylinder 2-stroke models. $44.17 for full details on carb settings.

 

[Zbhsmith]

Re: 89 nissian ns40c running problems

Thanks for the response, The only question I have now. Is the carb the problem? I would only assume that if the engine has good compression and spark, fuel and air is the only other thing I can think of that would keep it from running for more than five minutes.

 

[pvanv]

Re: 89 nissian ns40c running problems

Probably 85% of these problems are traced to the carb. But... In order to diagnose what area is the culprit, you need to do a full check of all the systems: mechanical, electrical, and fuel. Is the motor firing on time? (hint: a timing light comes in handy). Is the link-and-sync setup properly (hint: need the manual for rod and stopper settings). Is the carb clean and setup correctly? (hint: everything sparkling clean, and float height set so the float is parallel to the bowl when inverted.)

Running out of fuel (pump, needle, cracked fuel line, etc), could cause that problem. So could a gasket leak (brought on by thermal expansion). Or a CD (or exciter or pulser coil) that gets out of tolerance when hot. So there are a number of items that could lead to your symptoms. Start with the manual, go through everything from top to bottom, and when you're through, you will be confident that no gremlins are lurking under a reed valve somewhere.

 

[Zbhsmith]

Re: 89 nissian ns40c running problems

On the port side of the engine, there is a Yamaha part, it looks like the fuel pump. it that correct or a problem. I take a picture and post it if need be, but its raining outside now.

 

[pvanv]

Re: 89 nissian ns40c running problems

On the port side of the engine, there is a Yamaha part, it looks like the fuel pump. it that correct or a problem. I take a picture and post it if need be, but its raining outside now.

Hard to say from your description, but all the incoming fuel system parts are indeed on the port side. Inlet fitting, hose, filter housing, hose, pump, hose, carb inlet... in that order. The fuel pump (and gasket) is attached to the block, and operates on pressure/vacuum from inside the motor.

 

[Zbhsmith]

Re: 89 nissian ns40c running problems

Thats where im talking about, So that means there is a Yamaha fuel pump on this engine. Is that possible if So is it a good thing or bad thing. Could this be cause my problems.

 

[Zbhsmith]

Re: 89 nissian ns40c running problems

will this part work for carb. OEM # 345-87122-2 found it ebay.

 

[Zbhsmith]

Re: 89 nissian ns40c running problems

This maybe a dumbquestion but does the vent on the gas tank need to be open or closed for this engine.

 

[pvanv]

Re: 89 nissian ns40c running problems

will this part work for carb. OEM # 345-87122-2 found it ebay.

That part is the one, but it's an older one. The part number has been superceded to 345-87122-3.

 

[pvanv]

Re: 89 nissian ns40c running problems

Thats where im talking about, So that means there is a Yamaha fuel pump on this engine. Is that possible if So is it a good thing or bad thing. Could this be cause my problems.

The Tohatsu/Nissan part number is 356040001M FUEL PUMP ASSY. It's possible that Yamaha used a similar pump on some models.

 

[pvanv]

Re: 89 nissian ns40c running problems

This maybe a dumbquestion but does the vent on the gas tank need to be open or closed for this engine.

All OB's need to have the vent on the tank open to allow air in -- and fuel to flow to the motor. I would suggest that you download a copy of your owner's manual from http://www.nissanmarine.com/tech_talk/owners_manuals.html

 

[Zbhsmith]

Re: 89 nissian ns40c running problems

All OB's need to have the vent on the tank open to allow air in -- and fuel to flow to the motor. I would suggest that you download a copy of your owner's manual from http://www.nissanmarine.com/tech_talk/owners_manuals.html

Sorry for the dumb question, but first time boat owner, If the vent was closed would this be causeing my problems. The engine first ran for about 5 min then stopped. I could only get it to run agian for about a min at a time only after chocking it once.

 

[isaksp00]

Re: 89 nissian ns40c running problems

I'm not a mechanic, but think about it - if the vent is closed, you are sucking gas out of the tank, and new air can't get in. There's some air at the top, depending on how full it is. As the gas gets used, that air space reduces pressure, forming a vacuum. At some point, the vacuum is stronger than the ability of the fuel pump to suck the gas. Seems reasonable that a closed vent might cause fuel starvation after a few minutes. If the engine seemed fine in other ways, try it with the vent open and see.

 

[pvanv]

Re: 89 nissian ns40c running problems

Sorry for the dumb question, but first time boat owner, If the vent was closed would this be causeing my problems. The engine first ran for about 5 min then stopped. I could only get it to run agian for about a min at a time only after chocking it once.

Sure could...