where is my petrol gone

[neil parsons]

a strange one that i cant work out

when the car has been stood for 4 days or so , it then fails to start even though it turns over and wants to start'

.

the issue is lack of petrol , there is plenty in the tank,however the weber carb is dry as is the inline petrol filter. so off with the kn filter and fill the chokes up with petrol and she starts straight away. the carb fills with petrol and i can see petrol going through the in line filter'

.

maybe i need to carry some petrol with me forever

any suggestions , the petrol pump does look new as does the weber dftm

neil

[28ullkq4hau58]

its just run back to the tank,, or evaporated ,,

ther,s only the valve thats built in the lift pump  to stop it and they dont really seal..

[Dave Thomas]

I had a classic car with a similar  problem, turned out that the carb float valve was just staying open a fraction and the fuel was syphoning back to the lift pump which had a pin hole in its diaphragm, so fuel was going into the sump. So first thing to do is dip the engine oil to see if its getting higher on the dip stick, also take a sniff of the oil on the dipstick to see if you can smell petrol in the oil. If  theres no fuel in the oil   move on to the carb and check/readjust the float needle, Then if it still happens you could put a oneway valve in the fuel line between liftpump and carb to see if it cures it. Burton Power have the oneway valves.

[3a038xvsl2h4u]

Mines a bugger to start after a few days. Fine once you've wound it over for 20 seconds.

Might get one of those one way valves, you can't get bits for the Nikki carbs