Float Bowl Leaking

float level set wrong or leaking float maybe

If it sat long enough, you may have a corroded needle or seat. Or possibly some build up holding the needle open. Is the float still dry? Shake it and see if it's flooded.
Whatever the reason, your float needle valve is not closing properly.
This can easily flood the engine with too much fuel to start.

Take float bowl off...flip upside down...if the float isn't level adjust it so it sits level with the edge of the carb body...take 400+grit sand paper and lightly buff the needle...lightly...check to make sure jet is seated correctly also...

I rebuilt a ton of carburetors when I worked as a mechanic.

With the carburetor off the bike and float bowl removed, take a piece of new fuel line and attach it to the fuel inlet fitting. Invert the carburetor so the float presses the needle into the seat and try to blow through that fuel line. If you get any air at all through it in this manner you've got a leaky needle/seat valve.

I've never buffed a needle with anything. But if I were going to buff the needle I'd use something like a twenty dollar bill or if using sandpaper at all try 1500 grit. To clean out a varnish deposit on the seat I drip a bit of lacquer thinner on a q-tip and use it to swab out the seat. Do this two or three times and then blow out any residue with compressed air. Inspect the seat closely to make sure nothing is left on it.

To even out any irregularities in the seat, take a clean .125" steel ball - like those steel ball bearings in freewheels - and drop it down into the seat. With a small pin punch and smaller hammer lightly tap that ball then remove it.

Make sure that there is no sticking or side to side play when you check the float level. I made a new float pivot shaft with a piece of 14 ga bicycle spoke. Worked perfectly on the carburetor on my Honda 50cc

2door said:

7 days, no response. Maybe the OP figured out his problem. However for those that might have opened the carb and afterward have a similar issue, take a close look to see that the hinge pin that the float tang swivels on is seated properly and not overhanging the gasket surface. That pin can, and will, slide sidways and can block the bowl from setting flush against the gasket.

Tom

Click to expand...

Good point 2door.

I saw this happen a bunch as a motorcycle mech. Don't know if anyone ever managed to bend, damage, or break the pin and/or carb while attempting to seat the bowl to the carb body, but who knows?

As for managing to break off one of the cast "aluminum" float hinge pin bosses due to "corrosion" well, I'm that guy!

You just can't be too careful...