Help 19MM carb=no fuel flow.

[Superrat]

I just put my 70cc kit, pipe, carb, and filter on my scoot ran OK but too loud. put stock air filter back and dropped the needle runs fine noise level more acceptable. Played with it for a couple of days then but veriator on, and it won’t start. Crisp blue spark, no fuel. pulled carb apart all clean, float level OK autochoke flows on the bench and still flows at a reduced rate after hooked to battery for 5 minutes. I know it should be replaced (pisser new choke with less then 10-miles on it) anyway back to my sad story. Unhooked fuel line ran to cup ran starter got fuel flow and confirmed full float bowl. So I added a few drops of fuel into intake and put the carb back on and it starts right up runs until "added" fuel gone. Put stock carb back on and starts right up runs until I shut down. Anyone had problems with this carb not flowing fuel?

[Zuma-Zuma]

You've confirmed the vacuum valve is working. Do you have the vacuum line hooked up to the carb? Is your float or needle stuck? My vacuum line and fuel line would never stay on the Arreche carb. So I used a small zip tie, and problems are gone.

[Superrat]

I already have the zip tie and have confirmed the float bowl is full a couple of times by removing the carb and then the float bowl. Thanks for the help though! At first I thought that maybe the float was leaky so I pulled it and floated it in a cup of gas. It seems to float correctly so I held it under the fuel and looked for bubbles. None. It is like the pulse vaccum is too weak or a passage is blocked. Both the main/needle circuit and the pilot circuit are clear. Years of playing with 2-strokes and am stumped. It will turn out to be something stupid...

[Zuma-Zuma]

LOL, it always does. Is it possible the vacuum line is kinked or pinched? There really isn't alot in the way of getting fuel into the bowl. If you have a hand vacuum pump, try it and see if it gets the scooter running with all parts in place.

From reading your description of the problem, it sounds like a choke problem.....

[mopedmaniac]

i always just take the top off the carb, put the fuel line in the top and suck on the vacumum tube to add gas to the carb.it works just like a "manual choke." pain in the butt yes, but it does work for me.
hope that helps,
peace

[Superrat]

Found the problem: I adjusted the mixture screw and there must have been some machining burrs left in the channel. The mixture screw adjusts the pilot circuit. Anyway the burr did not fill the channel but did reduce it enough to cut the flow. Used a set of tip files and jet drills and opened it up and it again starts first kick. I knew the problem was somewhere in this circuit but my old eyeballs failed me. Thanks to all who responded to my call for help!

[Zuma-Zuma]

Thats funny. I had the same problem, trying to adjust the mix screw. After racking my brain too many times, I disassembled, and rather than cleaning, I inspected. And it was casting flash that was the culprit. Glad you got it fixed