Gas blows out exhaust after first start

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scooterdork
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Joined: Tue Aug 20, 2013 5:20 pm
Location: Salt Lake City, UT

Gas blows out exhaust after first start

Post by scooterdork »

I just finished a full carb rebuild with new gaskets down to the block, new float and needle, new jets. Scoot runs really well. But, in the morning after it has sat, it is grumpy getting started. I have to choke and open the throttle and after many kicks it will sputter to life and blow a puddle of gasoline out of the muffler.

Other threads have said this could be a stuck float, but when I open up the bowl it seems to be traveling fine and the needle works well. Some say to turn off the fuel after riding and let the engine run until lines are clear. Hmm..that seems weird to me.

Any thoughts on what it could be?
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Stanza
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Post by Stanza »

When you park it at night, are you shutting off the fuel tap? If not, I suspect your float needle (even though it's new) isn't seating/sealing properly, and you are getting a slow engine flood. If you are shutting off the fuel tap at night, you may be due for a new fuel valve seal, and it's probably not completely shutting off the flow.
scooterdork
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Joined: Tue Aug 20, 2013 5:20 pm
Location: Salt Lake City, UT

Post by scooterdork »

Thanks for the reply Stanza. I've just started shutting off the fuel tap when I park, esp at night and haven't had that problem since. So I'm wondering if the whole float cover part needs to be replaced - maybe it is warped.
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Mr.FixIt
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Post by Mr.FixIt »

This poor excuse for fuel that they sell us (ethanol contaminated) tends to harbor more moisture and cause corrosion in carburetors. The float needle valve may not be seating as well as it should be. Cleaning it out would probably solve the issue. Get in there with a Q-tip and scrub the seat.

A warped casting is unlikely, but could be checked with a straight-edge to prove it to yourself.

Its not a bad idea to turn off the fuel tap when parking anyway. I agree with Stanza ... the float is likely still leaking.
Eric
(aka Mr. Fix It)
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