Modern Vespa

Anyone shed some light on why the carbuerettor on my px200e is letting fuel through when its left standing for a few hours. If I turn the fuel tap off every time i park up it starts up fine, but if I leave the fuel valve open it floods.

I have tried cleaning the carb through and replaced float and float needle but made no difference. I am starting to think there must be damage to the seat that the needle seals against but it looks ok and theres no dirt in there as far as i can see. Not sure if there is a clever way to check or test it...

The carb is cmpletely standard apart form having the oil pump isolated (pipe terminated and gear removed)

Any advice much appreciated....

Nick

Yeah..if you leave the fuel tap to the "ON" position you are letting fuel into your carb thus if you leave it on the "ON" position..eventually it will flood.

See if you can start your scoot with the fuel tap to the "OFF" position. If it does, let it run until you have used all the gas out of the carb (it will eventually shut off due to lack of fuel). Let it sit for a while (still in the "OFF" position) and try to start it again with the fuel tap in the "OFF" position. It shouldn't start...if it does, then you have gas going to your carb while the tap is in the "OFF" position and that's not good. Maybe you have a bad fuel tap or maybe you are not sure which is "OFF" and "ON" on your fuel tap.

They are gravity fed you know.
Turn it off or get a pump and a snake of plumbing and more hassle

Somtimes if you have a new float you have to trim the ridge around it a lil bit. The newer ones have a bigger ridge around the seem and get hung up on the side preventing the needle from seating properly. It's flooding your carb with the remaining fuel in your line.
That is if your fuel valve is truly closed?
This is what happed to me.
There are other reasons too.
Good Hunting Brian...

I like to turn off the fuel tap when I'm up almost home, run the fuel out, then turn the scoot off. Just a habit...

ok - so you all turn your fuel taps off when you stop....thats what i'm now doing and it all fine.

But I never used to on my old px125, and my mate never touches his tap on his px200 so I'm sure there's a load of people who just leave the fuel tap on all the time without any problem

Your buddys must never stop riding or park their scoots.

when I transport the PXs on the truck they flood all the time, fuel valve off or not. If you suspect its flooded try starting it with the throttle wide open, don't worry it wont over rev, just smoke a lot till it clears. (the scooter, you too if you wish)

Thanks for all the advice - I will keep the tap religiously turned off from now on....when its standing still of course