Modern Vespa

Evening all,

I wonder if anyone can shed some light on my problem.

Engine has just been rebuilt replacing all bearing. (assisted by a friend)
It starts fine and ticks over perfectly.
I go for a 10 minute run and it cuts out, I try and accelerate to keep it running but it's as if its being starved of fuel. (fuel tap is set to open, and it has plenty in it).

Leave if for a minute or two and it fires up and off I go again.
My vespa knowledge is very limited...
What could it be, issue with the carb?
Would it be a mixture issue? It doesn't smoke...

Any advice would be superb.

sounds like a sticky float bowl in ya carb ... it could be stuck open just enough to get ya goin

Thanks, I will dismantle tonight and have a look.
Cheers

So, i had this same problem recently ...and i thought it was a sticky needle...replaced the needle and float and no luck.

Turned out that i hadn't tightened down the cap that goes on top of the fuel filter area enough, and it was leaking a small amount of gas out that filter.... not enough for me to notice at first, but enough that it messed up the entire float valve / fuel going down into the carb thing.

I could run the bike for about 100 yards, then it would outrun the float bowl....so i'd stop for about 10 seconds, and then it would fill up enough i could kick it over again and do the same thing.

Never had that happen before.

I've had this happen with a fuel line that is too long or misrouted.

Might also want to check that the vent holes on the gas cap are not blocked. Leave the gas cap open a bit and ride around. See if you have the same problem.

Have you checked the fuel filter on top of the float bowl? I have had the same symptom when I used a plastic fuel can to fill the scoot. Modern gasoline will slowly dissolve a red plastic can, and the resulting fiberous hair will plug a Verspa fuel filter. A fuel funnel with a built-in very fine (round) screen will show just enough contaminants in your fuel to stop a small engine.

Cheers and good luck,
Bob