Modern Vespa

The title says it all. Got a new bike and my carb seems to be running above 2000 rotations per minute. I am also noticing huge gas leak from the air filter compartment. The bike is dying after I get it started for a few minutes. I have played with a screw on the carb. My question is what is the procedure for doing that? Feedback would be appreciated. It's not a Vespa...

Can you find a forum for whatever brand it is to ask that question?

Dongfang Falcon 200 (169cc)?



Have you removed the low-speed mixture screw plug?

https://www.youtube.com/watch?v=GtYDHgPH6d8

Gas leaking from the air filter compartment is puzzling? MAY be a stuck carb float needle valve. SOMETIMES tapping on the carb bowl with a plastic screwdriver handle, or a pulse of compressed air into the fuel inlet port, will correct the issue.

If no joy . . .

https://www.youtube.com/watch?v=0DPcR-dvT50

https://www.youtube.com/watch?v=zlez_hdoWYk

Thanks Tortoise. I will study those video clips.

NightWing, I gave been looking for those sites. One thing is a problem. I don't speak Chinese! I am pretty confident that I will find the help I need over here. Thank you for your post.

I looked up Falcon 200 and all I found was airplane stuff.

What a coincidence! Piaggio makes airplanes too.

But I am not here to compare products. So back to my original problem. I am turning the top screw to the right as I open the idle screw on top. So turning it left is closing it while I apply the throttle to less than 2000 RPMs,. Correct?

This is odd. I bought the bike brand new and something like that happens. I believe I will call the manufacturer since I have the guarantee. I am just glad I tried riding it before putting it away for the winter so I found out there is a problem.

Again any feedback appreciated. The picture above is accurate. Mine is all black!

Almost certainly the float needle is stuck and the carb float bowl is overflowing. If the engine backfires, you'll have a massive engine fire, very bad. So it needs to be addressed sooner, not later. Pull the float bowl and see what is obstructing the float needle.

Generally the idle speed adjustment is on the side of the carb, and moves the slide up and down. Most carbs have a separate idle mixture adjustment.

It is not unusual for a high idle speed to result from a throttle cable with inadequate free-play. There should be just a little slack in the throttle cable, so the slide closes fully when the throttle is closed. Might need to check that also. Rotate the handlebars from full-left to full-right to see if that changes the idle speed. Sometimes a mis-routed throttle cable will cause problems.

I suppose I should mention that I know nothing about the specific scooter you have. But the above information applies to just about all scooters.

Wow! That is very useful information. Thank you. I will continue to work on it. VRM advised not ride the bike until this is sorted out since a gas leak may prove to be dangerous. More to come soon. I will try to take some pictures next time.