Wednesday, September 2, 2009

My Honda Moped Express NC 50 is LEAKING GAS!


What the heck? I have been riding my Honda moped to and from work (20 miles) for a number of days now. Granted my '78 Honda Express is 31 years old and problems are to be expected, but things were going so well.

Here is the deal. As soon as I had the Express in my yard and it was parked, I noticed that gasoline was litterally pouring out of a hose that connects to the Honda Express carborator and snakes down to below the engine. This tube serves as an "over-flow" for the bowl in the carb. So, if too much fuel is in the carb it has somewhere to go.

Well, I rotated the switch on the petcock from ON to OFF and the fuel stopped flowing out the rubber tube. It was going to completely drain my tank of fuel had I not done that. That took care of the immediate problem, and now I had to find a solution.

So, off to "Honda Express NC50 and Express II NA50 Mopeds > Honda Express NC50" on "Honda Express NC50 and Express II NA50 Mopeds - Message Board - Yuku" I went. Low and behold... I find a recent post for "1981 NC50 Leaking Gas". Someone described their problem as such:

"Just bought a 1981 NC50 about a week ago. It starts right up and runs great. However, gas keeps running out of a small tube underneath the engine, in front of the kickstand. I first noticed it when I turned off the engine after riding it. It stops if I turn off the fuel valve. Is this normal? If not, how do I fix it?"
After reading several of the posts, it seems that I might need a new express carburetor float, float pin, or mounting screw. I will have to open up the Honda NC50 carb to tell. I also need to find out where to purchase these parts... cheaply! You can get a set of all these for the rip-off price of $60 with shipping on Ebay... OUCH!

Here is service manual for Honda Express nc50 carburetor diagram:


One person posted the following as their solution that fixed the problem:
"So, I was dumb and didn't know that the cylinder thingy had grooves on it so your advice helped me, I just pulled it out, I was lucky I didn't damage it. The original problem was that I was leaking gas out of the carb. The needle wasn't closing off the seat. The pin that holds the float was bent so when it would sit one way it wouldn't push the float up to close the seat. We fixed it for a day because we just happened to put the pin in so that it laid well enough to close off the seat. We straightened out the pin and now it closes off that seat. It was frustrating taking that carb apart 10 times. Each time we thought we fixed it then wed get it all back together, turn her on and it would just pour gas out. Glad its fixed."

I am hoping once I get the carb open I will have a better understanding of what is actually malfunctioning. I will be sure to post photos of the process for others. Wish me luck!

You can find my next post of repairing/cleaning my 1978 Honda nc 50 Express carburetor here.

5 noped comments:

misha said...

how did it go? did you fix it? i've same problem

misha said...

ok, I fixed it by bending the float a little bit upwards, so it would push the needle more.

jfk said...

Misha! Thanks for your comment on my Honda Express nc 50 blog. Due to my busy schedule... I have not been able to fix my ped yet. I have my shed cleared out and hope to get working on it soon and get at least one more ride in before winter. I will most definitely try your suggestion, because it doesn't cost money! Thanks again.

parrish0083 said...

hi, I just the card fixed and everything is running all right. Although there is like a sprinkle or mist of oil coming out of the tailpipe and a lot of smoke. I was wondering if you might know about adjusting the oil flow or maybe the oil I m using is too thin? How would I cut back the smoke coming out of the tailpipe?

Rusty161 said...

Hi! I'm going to tell that you do a very great job with your website thanks a lot Mr. JFK!!

well, I putted that O-ring between the Jet and the Jet screw same as pictured above. I hope this will work fine because there wasn't that one when I unscrew that all. I'm running NC50 1982.

It's winter sleeping time right now so I will have to wait some months before riding it again...

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