Bongo Fury

I have fixed a fuel leak twice now, by changing the rubber fuel pump seal. It's back again today! I think the extreme cold may be to blame, somehow, as on warmer days the fuel often doesnt leak. Any ideas from you beautiful, intelligent people? as it is also causing a secondary problem of a leaky wallet..

Have you looked to see if it is leaking at the back end of the pump out of one of the set screw holes or around the edge of the domed cover which is in the middle of the four pipes going to the injectors?

Regarding the cold, I wonder if, because the fuel is more dense in cold weather, there is more resistance at the injectors so consequently pressure at pump seals will be higher.

I am assuming that the leaky wallet reference is based on wasted fuel.

It is not difficult to catch nearly all the drips and reuse them. My 'lash up prototype' drip catcher was simply a sawn off square section drinks bottle. My ultimate version, still in use, consists of a laboratory grade polythene funnel wedged under the pump with plastic tube jubilee clipped onto it leading to a narrow necked plastic bottle wedged down below and emptied as needed. When the weather improves I will try and post photos.

Because my mk.2 drip catcher is mainly enclosed the fuel is reuseable although I filter it through some blue roll paper as a precaution.

I check it approximately fortnightly as it is not filling very fast since I sealed the leak significantly with wet suit glue after thoroughly cleaning the pump exterior with methanol. in my case the leak was not from the 'usual suspect' seals at all. They may,of course start leaking if the internal seal is replaced but as that is a 'pump off' job it would be crazy not to replace them at the same time. Quotes for replacing the pump were frightening.



We owe it to our driveways and to motorcyclists not to let leaks get even as far as the engine tray. A heavy cloth in the tray helps and will not blow away. When mine was dripping at its worst the middle and rear underside was becoming 'self waxoyled'!


Frank

Hi if its the fuel pump seals leaking there is two of them opposite sides of the pump and can give the impressision that its leaking from the same area.. theres a very nice fact sheet on how to do this or seach topics

hope this helps Cheers Steve

p.s done mine about 3 weeks ago and its a fiddly job

sounds like there may be another problem if its reacuring. maybe put some pump cleaner through the system,it should clean everything out including the injectors.
maybe its a fuel pressure problem ?

Thankyou for the advice

Could my rather erratic fuel gauge be connected in any way? It hangs around half way, even when full and occasionally rises. I have no idea of the fuel level!

No...they are not connected problems.
For the gauge you will probably need to fix a "extra" earth onto the tank sender unit.....do a search for exactly how to do it....common problem