New Build - Numpty Fuel Line Routing Issue

[Yanker]

OK so I have just built a Lambretta with the carb on the 'wrong' side.

It has a carb with the banjo to the 'front'

The fuel tap is a 'normal' fast flow.

The fuel line routes down and under the left (large) engine mount, acoss the cylinder cowl below the frame tube, and then 'up and dowwn again' into the carb.

This seems to produce air-locks in the fuel line and VERY difficult starting with normal procedure. Once 'primed' or warm a very willing (1/2 kick) starter.

Reed valve (obviously)

Any ideas what's-up? (Thinking bad fuel line routing, leaky carb banjo (no sign tho), float height too high, leaky float needle - though carb is as good as new and behaves when the fuel flow is there)

Ta for input!

[Yanker]

you have answered your own question


"Carbs on the wrong side"

Fanx! Youwz full of humour 2nite intja?

[Yanker]

Graaayt buwtt sereeeouwz anszwaz is alshohe arpreshiahted. iyuf ver is annyfink?

Or in the queens " great, but serious answers are also appreciated, if you have got annything?"

At all. to help. this distressed mod?

[Yanker]

So what , just tip my carb upside-down then?

Where are all the TS1 and RB f****n experts...does anyone build their own engine anymore?

[Muttley McLadd]

but serious answers are also appreciated,

Put a tank of 98 through it. It's lighter than normal fuel, and the bubble will sink to the bottom of the pipe. Once it's gone, it's gone.

[nelson pk]

If your getting vapour locks in the line it's getting air in somewhere. Did the fast flow tap come from a reputable source.
My mate bought 2 fast flow fuel taps off ebay when he finished his RB build. In both taps the washer was shagged from new and caused vapour locks.
If its not that look at the fuel line its self.....the really bendy floppy pastic fuel line is s**t and will allow air in through the pipe/tap joint no matter how tight your jubilee clip is.
Other than that look at your fibre washers on carb banjo.
Oh and i wouldn't route your fuel line over the cylinder cowling. I have done this in the past however i've been told not to by a well respected tuner.

[joeswoonara]

au reet me duck ! ........i run a rear entry f/flow fuel tap and run the hose toward the bumpstop , but not over it.......then round the back of the mount and on to carb .......gentle gradient bubbles vent into tank

[coaster]

The important thing is what is the fuel flow like? if it flows enough fuel with the bubbles then it's probably nothing to worry about.

[Yanker]

au reet me duck ! ........i run a rear entry f/flow fuel tap and run the hose toward the bumpstop , but not over it.......then round the back of the mount and on to carb .......gentle gradient bubbles vent into tank

Lingo! Sort some decent (BGM) hose, re-route, jubilees instead of springs and try again! Fanx! Tara mi ducks.