NS9.9c carburetor problem (maybe)

[oklahomariverfisherman]

This motor had been sitting for a few years, but it appeared hardly used before that. It took alot of pulling, but I got it started. I used the reccomended method of 3 minutes idle, 5 minutes lowest speed, 10 minutes middle speed. After this I revved it up a bit and had it running at higher rpms. It revved up a bit more on its own sputtered a couple times and died. Now it will only idle for the first few seconds when starting. After that it seems to only want to start when pulling, not using the elctric start. It will not idle. You must give it some throttle to keep it going. Sometimes the throttle will make it sound like it is burping, and it will die anyways. Sometimes it will accelerate almost normally. I pulled the carb off and cleaned it out. My repariman thinks the problem is in the carb. He lives an hour away and I prefer to fix this myself if I can. I would appreciate some advice.

 

[TOHATSU GURU]

Re: NS9.9c carburetor problem (maybe)

Clean the carb corrrectly and try it again.

 

[oklahomariverfisherman]

Re: NS9.9c carburetor problem (maybe)

Sorry man, I guess I forgot to include that part even though I originally meant to. I took the carb apart and cleaned it. We also checked the fuel pump diaphragm and it appeared good. It is not leaking from the fuel pump so we assume that gasket is fine as well. The main jet seems fine as I could blow through it. The float seems free as well. I took the top off which has a rubber piece as well which looked fine, and the apparent vent was not blocked either.

 

[TOHATSU GURU]

Re: NS9.9c carburetor problem (maybe)

The "correctly" was the important thing. You took the carb apart, sprayed a carb cleaner on it and it and thought you did something....And you did. You made it shiny What you need to do is take it completely apart, dip the carb body and it's metal bits into a one gallon pail of carburetor dip for three hours, rinse it out with water, blow it dry and then put it back together. Spray cleaners are to weak to get to the blocked ports and passages in the carb that are not visible.

If that doesn't work, you look at the rest of the fuel system and then move on to the ignition and mechanical systems...Using the repair manual as a guide.

 

[oklahomariverfisherman]

Re: NS9.9c carburetor problem (maybe)

Ok, point taken. I will try to locate a repair manual, take the thing apart (kind of scary), and give it a proper cleaning. I need to remove the fuel pump from the side and just clean the main carb body and parts? According to the parts manual that should give me about 29 parts. The butterfly and inner workings stay inside? I think if I am going to this this length I should just replace the rubber peices as well gaskets, and fuel pump diaphragm since I have it apart or should they all be fine after sitting a few years?

 

[TOHATSU GURU]

Re: NS9.9c carburetor problem (maybe)

"I need to remove the fuel pump from the side and just clean the main carb body and parts?"

You need to remove all rubber and plastic parts where found.

"The butterfly and inner workings stay inside?"

Yep

"I think if I am going to this this length I should just replace the rubber pieces as well gaskets, and fuel pump diaphragm since I have it apart or should they all be fine after sitting a few years?"

They should be fine, but, due to alcohol in the fuel they warp and deteriorate faster than they used to. If they look deformed or stretched you should replace them.

The following is a soapbox announcement

Spray cleaners are extremely mild in terms of strength. Call them a one or two. Carb dip is more like a seven or eight. When you have a problem you use dip. If you have a perfectly running engine you use spray as a PREVENTIVE agent, once per month to catch the varnish before it builds up. Also, run the engine dry after every use. It cannot hurt the block or pistons and eliminates 98% of the fuel in the bowl. Tickle the choke as you run it dry and you can get the last 2%. Only use fuel less than 30 days old. And finally, fuel stabilizers keep the engine fuel from rotting quickly. Unfortunately that is not the problem. Fuel evaporation and water in the gas are your primary concerns. Clean, fresh fuel, therefore, is your best defense against future problems.

 

[oklahomariverfisherman]

Re: NS9.9c carburetor problem (maybe)

Thanks a bunch. I planned to remove all the rubber, I was more thinking of the fuel pump body, but I guess you addressed that when you said start with the carb and work your way to the rest of the system. I'm a bit concerned about getting it all back together. It is always less daunting after you have taken it apart, it is just that first step.

Thank you for the added advice. You are saying that I need to take the carb apart every month and spray it or just run the spray through the carb? If you are meaning run it through, why not just add some berrymans to the gas? Same goal accomplished or is it too diluted in the fuel? I am definitely glad to have a guru on my side!

 

[TOHATSU GURU]

Re: NS9.9c carburetor problem (maybe)

The body is plastic and does not need to be dipped. You don't have to take the carb apart unless it has trash, water or built up varnish in it. Basically, what I would like to see you and everyone else in the world do, is to shoot a burst of spray cleaner in the carb, once a month, while the engine is running. Rev the engine up to about 1500 RPM and spray until the engine starts to choke down. As soon as it sounds like it is going to die, let off the spray and let the engine fully recover back to its RPM. That's all there is to it.

 

[Sea Rider]

Re: NS9.9c carburetor problem (maybe)

what I would like to see you and everyone else in the world do, is to shoot a burst of spray cleaner in the carb, once a month, while the engine is running.

Have nothing against the procedure, but spraying carb cleaner directly into carb while engine is running, the only issue you will be cleaning for sure is the carb's butterfly, internal throat, reed valves but not interior small & narrow parts as when stripping down a carb. Besides a cosmetic clean look, it's a waste of precious product.

Better would be to add car carb/inyector cleaners to mixed gasoline/oil as to clean internal carb parts & passages while going at fast speeds for prolonged time periods. In a car works perfect, should too on outboards. Any experiences ?

Happy Boating

 

[TOHATSU GURU]

Re: NS9.9c carburetor problem (maybe)

The point of the spray cleaner is to use it while the engine is healthy....As a preventive measure. It is useless to solve a problem, but it can help prevent one. In this case it can and does get sucked through the needle valve along with the fuel. This will help prevent the needle from sticking and will dissolve any initial surface varnish throughout the carburetor...It also releases minor amounts of any built up carbon in the block. It is not a waste of product....But, it does make them shiny too

 

[oklahomariverfisherman]

Re: NS9.9c carburetor problem (maybe)

Awesome information. My father in law got nervous thinking of me taking the carb apart (funny thing is I already had it off and taken in half), so he is taking the motor to the fix it man. I was actually looking forward to seeing if I could fix it, but with a wife, son, and graduate classes I will take all the help I can get! Now if I can just find the right boat. Man, I'm ready for some fishing!

BTW- I will be following advice and keeping my motor in tip top shape once it is right.

 

[Sea Rider]

Re: NS9.9c carburetor problem (maybe)

Ok, the point is valid, what about using from time to time carb cleaner mixed in proportion with gas/oil in tank and cruising al 3/4 to clean all interior carb parts including carbon deposits on piston heads while engine is working ? has anyone tried this ?

Happy Boating

 

[TOHATSU GURU]

Re: NS9.9c carburetor problem (maybe)

Not me...But, I have never seen any of the magical improvements that are touted by all the products sold for autos either. A lot of the "Yankees" on iboats swear by an additive called Seafoam. It must do something because they all begin to salivate while promoting it I can't recommend it because I haven't used it, but there are enough of them that do swear by it that it probably will clean up minor varnish to higher degree than I might suspect. However, generally anything that will dissolve heavy biological deposits has a negative effect on the oil used to lube the pistons and walls. There is a tech up in Pennsylvania that knows as much, if not more, than I do. I'll ask him what he thinks and let you know.

 

[Sea Rider]

Re: NS9.9c carburetor problem (maybe)

There is a tech up in Pennsylvania that knows as much, if not more, than I do. I'll ask him what he thinks and let you know.

That would be nice to know about, car/injector cleaners works perfect for me, as only pure high grade gasoline is available down here, the idea would be to add 1/4 bottle to treat 5-6 gallons and consume complete tank at high speed during the day out.

Happy Boating

 

[oklahomariverfisherman]

Re: NS9.9c carburetor problem (maybe)

Tohatsu Guru- I just wanted to update you on what was wrong with the motor. The man at the shop took the carb apart, and soaked it in carb soak. He pulled it out and blew out the passages. It runs as good as new, but it cost me alot more to get it there! Thanks again.