Fuel problem

markg · Post by **markg** » Sat Mar 07, 2015 9:42 pm

Just looking for a bit of advice. Took my Exup out for a spin today. All was well for about 20 miles when the bike started to cut out, flicked the reserve switch as the tripmeter was up at about 100 miles which would be about right given how many times the bike has been started over winter.
Bike eventually cut out and would not re start.
Looked in the tank and had petrol, took the hose off the fuel filter and had a flow of petrol. Tried to start bike again and it was fine. A couple of miles down the road and the same happened, repeated what I did the time before and started again.
Filled with petrol a bit further down the road and then the bike ran fine for the 30 odd mile trip home.
Am I looking at the electric fuel switch being knackered or should I be looking at something else?
All advice greatly appreciated :-)

Teego · Post by **Teego** » Sun Mar 08, 2015 12:37 pm

I'd have a look at a couple of things first.
Is the tank breather clear?
Could be crud in the fuel system. Check both filters. People forget the little one at the carb end of the pipe.
Could be the fuel pump.

markg · Post by **markg** » Sun Mar 08, 2015 5:07 pm

Breather is ok. Will check the filters though. Fuel pump seems ok. May have just sucked some crap through the system as the tank was low.

rdgravy · Post by **rdgravy** » Tue Mar 10, 2015 7:26 pm

I had the same problem last summer. Which probably means I'll have the same problem this summer too because I know I didn't fix it. Bike runs fine until I get near reserves and when I do get onto reserves it takes age and ages to start again. I did notice that if I opened the fuel filler cap and let some air in it seemed to be fine. It really ought to be on my job list soon.

Vagabond · Post by **Vagabond** » Tue Mar 10, 2015 10:56 pm

I'd something very similar happen to me, turned out it was the reserve switch was dirty so when I hit reserve nothing happened, the only way to get the bike started was to prime the carbs by turning the kill switch on an off before hitting the start button.

Cleaned the reserve switch up and it was fine.

oldskoolexup · Post by **oldskoolexup** » Wed Mar 11, 2015 11:23 am

Well worth cleaning contacts of reserve switch with a good switch cleaner to eliminate this as a potential source of issues.

markg · Post by **markg** » Wed Mar 11, 2015 12:51 pm

Cheers guys, that's given me a few good things to look at.
Going to change the filters, replace the fuel hose from the tank and check the wiring / clean connectors.
Probably will try to avoid going on reserve ever again but hopefully never have the issue again.

markg · Post by **markg** » Sun Mar 15, 2015 9:43 pm

Turns out to be a wire broken off the switch.
Have soldered it back on but not convinced it will hold.
If the two wires from the switch are joined, does it bypass the switch and disable the reserve?

Post by **Stig** » Sun Mar 15, 2015 10:07 pm

depends if its an open or closed circuit

EXUPNutter · Post by **EXUPNutter** » Sun Mar 15, 2015 11:01 pm

I don't have the reserve switch on my track bike but can't remember whether I had to join the wires or just unplugged it.

willandrip · Post by **willandrip** » Mon Mar 16, 2015 5:28 pm

It's a normally closed circuit.

If the circuit becomes open for any reason, either switched to reserve or a fault occurs/wire breaks in any part of the system including the sensor (which is prone to this) then the bike will by default run the reserve circuit override and hence run the tank dry.

Corrected it for you will. Moderator.