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Petrol tank hoses
Posted: Mon Apr 14, 2008 9:34 pm
by gasfireman
Ran out of petrol yesterday right by a garage fortunately.
Loads of fuel visible in tank and still some showing on gauge.
Only managed to get 15 litres (21 litre tank) so lots still in there.
Could it be the hoses for the feed and pump return are reversed where they exit the tank?
Suggestions please ,,,,
Re: Petrol tank hoses
Posted: Tue Apr 15, 2008 12:25 am
by Tamburinifan
Could it be the hoses for the feed and pump return are reversed where they exit the tank?
Wouldn`t even start if that was the case, I think.
How did you determine it was lack of fuel that caused the stop?
Re: Petrol tank hoses
Posted: Tue Apr 15, 2008 5:45 am
by ducapaso
just have a look to the fuel filter, if it's empty (and the pump is running!) this might be.
otherwise, you can go debugging various causes, such as:
1) pump not running (of course!)
2) filter too mutch dirth
3) conic valve inside the carb float locked
4) pipes clogged
Have a nice work, and....
Re: Petrol tank hoses
Posted: Wed Apr 16, 2008 10:16 pm
by gasfireman
Have experienced fuel starvation on other bikes before and its not unlike running onto reserve tank.
Took bike out last night and after sustained high speed run up gradient on M4 from Severn bridge bike just cut again. Got it going after a while.
Stripped it tonight, filter in tank badly blocked hence not able to drain totally and inline filter needs changing too. Fuel pump sucks hard if I stick my tongue over end of it so thats all ok. Just annoyed with myself that I never went through fuel line when I bought it last year. Will treat it to new hoses, filter, a tank flush etc tomorrow.
Re: Petrol tank hoses
Posted: Wed Apr 16, 2008 11:39 pm
by Tamburinifan
OK, thx f sharing!
Tell us the result of your work.
Re: Petrol tank hoses
Posted: Thu Apr 17, 2008 1:06 am
by ducapaso
By the way... there's a net strainer inside the tank, fitted upon the petcock: it might be full of sand and rost!
Remove carefully the petcock and be careful not to damage its seal!
Re: Petrol tank hoses
Posted: Thu Apr 17, 2008 4:20 pm
by gasfireman
Went through entire fuel system.
Filter 1. In tank on fuel tap, badly blocked with coarse muck, paint chips, silcone balls?? etc- Drained tank totally and cleaned through tank, got all sorts of muck come out
Filter 2 - In line - again blocked but with fine muck
Filter 3 - On entry to carb, blocked with fine particles, I think this may be inside of fuel lines perished
Float bowl - Very fine black dust in bottom. Must be Houdini dust to get thro those filters.
Cleaned and checked jets.
Replaced all hoses and clips. Need to get 8mm Y piece for fuel line to finish job.
Hopefully thats got it sorted.
Re: Petrol tank hoses
Posted: Fri Apr 18, 2008 5:43 am
by ducapaso
Usually "Y" pieces are used in windscreen washer pipes. Any automotive supplier should help you. Otherwise, a steel one from an high pressureair plant of industrial machinery

Re: Petrol tank hoses
Posted: Sun Apr 20, 2008 4:31 pm
by gasfireman
ducapaso wrote:Usually "Y" pieces are used in windscreen washer pipes. Any automotive supplier should help you. Otherwise, a steel one from an high pressureair plant of industrial machinery

Most of the automotive Y and T pieces on sale here are smaller than required and in plastic. I dont like clamping joints down too much and have a thing against plastic fittings in fuel lines especially the pressurised side of the pump, where if they fracture the bike could catch fire.
I went to an LPG centre where I got a brass Y piece for £1.67 - bargain - oh and it was Italian made!!
Incidentally the plastic Y that came out had a jet fitted in the return line back to the tank. This could have caused low speed pressurisation and flooding into the float bowl. I know low speed fuelling was a problem with these anyway and reckon this could have made it worse.
To prevent the fuel pump pulsing the float needle off its seat some people use a pressure relief valve. I am trying a different approach by putting a longer fuel line between pump and carb which will hopefully damp it all down a bit.
Re: Petrol tank hoses
Posted: Fri Apr 25, 2008 5:43 am
by ducapaso
[quote="gasfireman]
Incidentally the plastic Y that came out had a jet fitted in the return line back to the tank. This could have caused low speed pressurisation and flooding into the float bowl. I know low speed fuelling was a problem with these anyway and reckon this could have made it worse.
To prevent the fuel pump pulsing the float needle off its seat some people use a pressure relief valve. I am trying a different approach by putting a longer fuel line between pump and carb which will hopefully damp it all down a bit.[/quote]
The jet was meant to prevent a "shortcut" of air bubbles in the pipelines, but it had never workgood

That's the reason why I made my own pressure valve and put it in the same place of the jet (Remember it needs a very low press setup!, about 3 or 4 psi!)
Re: Petrol tank hoses
Posted: Tue Apr 29, 2008 8:30 pm
by gasfireman
Mine seems to be running ok now.
The cutting out I could have sworn to be fuelling continued when hot even after doing everything in the fuel system.
In desperation I went through the ignition system. I replaced plugs, leads, cleaned all connections and coil earths etc etc. Even though it was all a bit tatty, there was nothing seriously wrong and the problem hasnt come back yet. I suspect the problem was Champion plugs, it wouldnt be the first time so made sure I fitted NGK. Cured??? I hope so