5 replies to this topic

[PJ266]

mini mayfair 998cc:
1984:
blocked fuel line:


Hi there, managed to stupidly run out of fuel today, filled it back up but now it wont start which makes me think some sediment must have been sucked into the fuel line. Any advice on how to clear them?? possibly blow them out with a compressor/track pump??

Thanks for your help, Paul.

[dklawson]

While it may be that some debris has been stirred up, I suspect that the fundamental problem is that the pump has lost its prime and there is air trapped in the lines. The pickup tube in the tank is not on the very bottom and it has a coarse screen on it to prevent debris from being sucked up.

I would disconnect the fuel hose at the carb and temporarily fit another short length of hose to the carb. Using a funnel I would manually fill the carb's float bowl with fuel. With the float bowl full the engine should start and run for a minute or so. The engine will be running faster at idle than it does on the starter and this may allow the pump to regain its prime and begin pumping again. If you have a translucent filter inline between the pump and carb you will be able to see the restored fuel flow.

[bmcecosse]

If you really think the delivery pipe is blocked - just blow through it back to the tank. But I do suspect that dkl is correct in his suggestion. Try simply blowing into the fuel filler - seal it off with a clean damp cloth leaving a small hole in the middle - and then blow like mad!

Edited by bmcecosse, 08 May 2011 - 06:53 PM.

[PJ266]

Thanks for the help, will give it a go tomorrow and see if I get anywhere!

[PJ266]

Ok so theres fuel being pumped upto the carb, took the dashpot off the carb and blew it through with a bicycle pump, put it back together and it still wont start up. Will fiddle around a bit more before I take the carb off.

[dklawson]

took the dashpot off the carb and blew it through with a bicycle pump, put it back together and it still wont start up. Will fiddle around a bit more before I take the carb off.

Do you mean you used the bicycle pump to blow air down through the jet into the float bowl?

You know fuel is getting from the pump to the carb. It sounds like you have made sure the jet is also open back into the float bowl. That leaves the float valves themselves.

A quick test will be to spray starting fluid down the carb throat (or tip a thimble of gas down the carb throat) and turn the engine over on the starter. If the engine fires up and promptly dies, you have a fuel delivery problem. Is this an SU carb and if so, is it an HS or HIF series?