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Fuel leak

Posted: Thu Jan 09, 2020 6:46 am
by Vintage man
Morning all

Got a 1600 TP with a solex 34 pic carb.
Noticed that fuel was running out of the butterfly shaft ,both sides that was after traffic driving coming home from work.Monday.

Last night idled the bus got it warm and no leaks untill I switched off and fuel leaking again out the shaft.
The shaft bushes don't feel bad at all.
Checked the float seems fine.Please what to check next as I don't think its the bushes but flooding causing the leak as there is fuel in the engine oil.
Any advice to guide me to the source of the problem will be greatly appreciated.

Re: Fuel leak

Posted: Thu Jan 09, 2020 8:16 am
by calooker
Needle & seat is toast, or the fload level is way out.

Re: Fuel leak

Posted: Thu Jan 09, 2020 8:31 am
by 73type2
Maybe your fuel pump pressure is too high - pushing fuel past the needle and seat.

Re: Fuel leak

Posted: Thu Jan 09, 2020 10:31 am
by Vintage man
Thanks for the advice ,new needle and seat ,mechanical fuel pump? so if switched off would there still be to much pressure.I read about the fuel pump push rod and do have the shorter one out of the 2.

Re: Fuel leak

Posted: Thu Jan 09, 2020 1:25 pm
by Ricoffy
I would also check the fuel pressure. I am not sure whether the mechanical pumps keeps the pressure after switching off - maybe some of the more experienced members can comment on that - but in my mind: as it is a mechanical pump driven by the engine, I would wager that after switching off the engine, the pump would automatically keep the pressure (and if too high it will flood the engine even after switching it off).

Re: Fuel leak

Posted: Thu Jan 09, 2020 1:56 pm
by Vintage man
Thanks Ricoffy ,would also like to know if the pressure stays when switched off.

Re: Fuel leak

Posted: Thu Jan 09, 2020 4:08 pm
by retrovan
As the pump has two one way valves, the pressure will stay if you do not have a leak.

Me thinks your old needle and seats can not hold the pressure of the pump.

You can adjust the pressure of the manual pump by shortening the shaft, or increasing it by welding a bit on, BUT only do this once you have a pressure gauge.

It must be able to read 3psi at max scale on the dial,to be accurate.

Herman

Re: Fuel leak

Posted: Thu Jan 09, 2020 4:53 pm
by Vintage man
Thanks Retrovan ,

Re: Fuel leak

Posted: Thu Jan 09, 2020 5:36 pm
by Terry Phillips
Stupid question if you made a thicker gasket to the pump brining the pump further out and the pump push rod will not get full travel. :?:

Re: Fuel leak

Posted: Thu Jan 09, 2020 5:42 pm
by retrovan
Will work, also great idea.

Herman