Spitting gas when not running

[Beefer]

A young girl that works in the pizza joint next to my store has a scooter, and it spits gas when it's turned off. I know nothing about scooters. It dribbles, drips, and then spits gas out of a lower clear tube coming off her carb. Anyone know what is causing this, and how we can fix it? Sorry, I have no clue as to make, model, engine, etc.

 

[EddiePetty]

Re: Spitting gas when not running

...that "lower, clear tube" on her scooter should serve quite the same function as the clear tube on our I/O's fuel pump.....but, being a terra-firma kinda vehicle, the fuel is allowed to drain to Mother Earth. As the tube is on the carb, excessively high float, leaking needle valve or excessive fuel pressure is surely the culprit. (If the fuel tank is gravity fed, vent closed/blocked, a hot day...thermal expansion may blow the needle of the seat). If she has a fuel shut off valve, have her close it when parking the scooter.

 

[Beefer]

Re: Spitting gas when not running

Yeah, that's what I was thinking too, that it's like ours on our I/O's, but there is also another clear tube above (what looks to be) the carb. She didn't know of a shut-off for her fuel, and I couldn't find one. I'm worried this kid is gonna blow up one day.

 

[marlboro180]

Re: Spitting gas when not running

It is the overflow line from the bowl of the carb, and the needle valve is not shutting off the fuel properly, and it is continuing to fill due to the fuel tank being above the carb. Think gravity feed..., with the fuel above pushing the fuel in the carb out through the clear "vent" line, and onto the ground.

She needs a minor carb rebuild, with a new needle valve and possibly the seat.

There may also be a vacuum operated petcock on the tank which may be failing. I have seen that type fail several times on my previous bikes, causing a fuel dump, or just plain old flooding the engine. My resolution was to get rid of them, and put on a manual petcock.

Hope this helps.

M

 

[Beefer]

Re: Spitting gas when not running

Thanks! If she's working today, I'll try and tinker with it for a bit.

 

[642mx]

Re: Spitting gas when not running

Yep... the float valve isn't sealing. On some scooters, they will leak when the scooter is left on a side stand for long periods of time. If it has a center stand, use it and see if it keeps dripping.

As someone mentioned above, 99% of scooters have a vacuum activated petcock. When the scooter starts, the vacuum off the carb opens the petcock allowing fuel to flow. When the vacuum shuts off, it closes. The shop that I run sells the eton brand, in the past 9 years I think I've sold one petcock, they don't fail often. But we have sold a bazillion float valves.