Vespa Px fuel supply problem. Please help

[mancpete]

Hi guys. I am hoping you might be able to help me with this issue.  In short it is as follows:

the fuel is not getting from my tank to my carb. I can see the fuel in the fuel pipe (because it's clear) and it's just stopping short (about 2cm) of the carb. I know the fuel tap is ok because I took the tank out and tested it. It flows fine? 

Now the the longer story:

i replaced the the fuel tap with a bgm fast flow fuel tap and new clear fuel pipe. When I first started the scoot up it was fine. I stripped and cleaned the carb and replaced all the filters etc. I went for a ride, all good. Now when I come to start the bike again after it being stood a while it spurts into action just using the bit of fuel left in the carb, but then soon cuts out as no more fuel is getting through. As I say I can see the fuel in the pipe but it's not flowing into the carb ( still about a 2cm short of reaching the carb inlet). I took everything apart agin, blew some air out of the fuel pipe and reconnected it. It started up fine. But then again when I leave it for a while the fuel is not getting through. It's back to square one where I can see it in the pipe but it's not reaching the carb? 

I wonder if if the pipe is too long? 

Any suggestions would be greatly appreciated? 

[jedihunter]

Sounds like the fuel line is either kinked or too long.I would try opening the fuel cap, and seeing if the fuel makes its way to the carb, if it does then the breather hole is clogged, if it doesn't check the length of the fuel line.
Good luck!

[ianmartin40]

Probably also worth checking carb float needle and seat to make sure no blockage at carb end

[mijapxman]

As mentioned by jedihunter or maybe a blockage in the fuel tap with crap from the tank?



Check this out 👇



Good luck.

Mij☺

[mancpete]

Nar. I've checked flow from the tap and it's fine when the tank is out. It's just when I reassemble. It's not reaching the carb. Scoot is in lockup so going to try shortening the fuel pipe this weekend. Cheers

Just one other question. Should the carb suck the fuel as I kick it over. Or does it only do that once running?

[annsummers]

Hello all,
I've just started with the same problem, no fuel!!!
This is my second SIP FF tap in a few months.Just fitted the latest model (2) tap, electronic type. New hose, very short, no filter. Ran OK for about 100 miles. Scooter not used for about a week. Started up today, it ran for approx 0.5 mile, it kept cutting out. Checked fuel from banjo on carb, 0 fuel coming through.
Tap operates OK, but dry as a bone. Looks like the tank is coming out AGAIN!!!

[annsummers]

Hello all,
I've just started with the same problem, no fuel!!!
This is my second SIP FF tap in a few months.Just fitted the latest model (2) tap, electronic type. New hose, very short, no filter. Ran OK for about 100 miles. Scooter not used for about a week. Started up today, it ran for approx 0.5 mile, it kept cutting out. Checked fuel from banjo on carb, 0 fuel coming through.
Tap operates OK, but dry as a bone. Looks like the tank is coming out AGAIN!!!

[annsummers]

Hello, latest update, looks like the fuel hose was kinked somehow?? A bit strange how it could just kink by itself??. Lifted tank out, suspended it above scoot.turned on tap, fuel flowed as normal. I've noticed SIP sell a fuel tap adapter for about £5.00. Its a tubed 8mm horse shoe shaped tube with 2 jubilee clips. I think the idea is to attache adapter to tap outlet, directing fuel hose towards the front of scooter instead of left side, eliminating the possibility of a kink in hose?

[pana1]

I have the opposite problem... a lot of petrol going into the carb..and unburned then to the exhaust...do you think is the needle?