Carb pours gas... Help please

Guys,

I drove my Columbia moped today for the first time. I love it! It has one problem, though...

The carb was rebuilt by the previous owner, and the moped runs/looks great...

But.. When I drove it today, gas was pouring out of the carb as I rode the moped. Any ideas what could be wrong?

Just to give you guys an idea- my carb is mounted under the engine, and it has a cylinder-like air filter mounted on the carb.

I THINK it's coming out of the air filter...

Thanks guys,

EK

Re: Carb pours gas... Help please

Check the Fuel inlet needle for dirt, check float malfunction, lost bouancy

Re: Carb pours gas... Help please

Pepied,

Thank you so much, I appreciate the help.

Re: Carb pours gas... Help please

YUP, clean the whole carb, and concentrate on what pepied said. your inlet needle isn't stopping the gas flow.

Re: Carb pours gas... Help please

Don Pflueger /

it should take 4 or more lbs of air pressure to blow one open.

Re: Carb pours gas... Help please

That is easy to test..

Since a column of water 2.31 feet high makes one pound of pressure, 4 pounds means a float needle should stop flow from 111 inches (9.24 feet) of a water-filled vertical hose. Seems like a lot of pressure..

Re: Carb pours gas... Help please

Guys, thank you so much for your advice. I really appreciate it. As soon as the weather warms up again, I will apply what I have learned from you guys.

EK

Re: Carb pours gas... Help please

Jason Luther /

yeah, thats _real_ easy to test. heh heh.

Re: Carb pours gas... Help please

i was gonna do it.. might still do it just because i think 4 pounds is way too high to expect.

i have some clear plastic hose that will fit the carb inlet.. Remove the bowl, put the carb on the floor and fill the tubing with water. Raise the end of the tubing until water leaks past the float needle.

Measure the height of the water level in the tube when the valve leaks. (Actually it will stop leaking and reach some stable level) Multiply that (in feet) by 0.43 and you get pressure..

Lets say water level in the tube is 6 feet above the inlet when it leaks.

6 x .43 = 2.58 (pounds of pressure)

Re: Carb pours gas... Help please

oops.. the bowl has to be on the carb because the float has to be floating .. it can't just hang down since that will give a falsely high reading ..

.... because only a portion of the float's weight is actually pushing on the needle when the float is floating on a pool of fuel..

But still, whenever water pressure is high enough to leak and drip out of the carb's overflow or vent, that's how much pressure the needle can withstand.

Re: Carb pours gas... Help please

Don Pflueger /

your mouth can create almost 3 lbs of pressure. try to blow a needle valve open when the carb body is held upside down with the float and parts mounted.

Re: Carb pours gas... Help please

Don Pflueger /

you have too much time on your hands joe. that figure i posted came from a tecumseh or a zama carb school book. i cant remember which.

Re: Carb pours gas... Help please

When i'm curious about something i see it through..

i did a little experiment.. used 10 feet of tubing on a spare carb.. Pressure wasn't even close to getting past the needle..

i will be more careful and use a pressure guage and air and do this right and report back..

Re: Carb pours gas... Help please

LOL guys,

Both of your methods are great... LOL... Thank you both. :O)

EK

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