[ChrisR]

Hi all,

Does anyone know whether there's any in-line fuel filter fitted - either in the pump or the injector? Reason I ask - I briefly experienced some very rough running for a short time.  Now everything's fine, all cured by itself.... ? Which bothers me. If the bike was carburetted I'd have put it down to some dirt in the idle circuit - as that's exactly what it felt like. I've checked and cleaned both the fuel pump and injector relay contacts (yup! both absolutely smothered in some light coloured lithium based looking grease) I have replacement relays on order from Hitchcocks - just-in-case. The side stand engine disable switch I removed some time back - so it's not that. Hence my question. It's not the plug either. Has anyone experienced a dirty injector ?

Thanks in advance for any input! 

[Desi Bike]

There is a small screen filter on the fuel pump inlet.  As you are probably aware, the pump is on the tank.

 In the past,  several owners have found the the paint overspray during the manufacturing process has been 'eaten' by the poor quality of American fuel.  The American fuel is commonly contaminated by corn ethanol.

I'm Canadian,  and only began experiencing fuel issues when I started riding in the US. Seems like the ethanol eats into the rubber lines and the paint overspray leading to clogging of the fuel pump screen.

The ethanol in the American fuels also creates an issue with water  from condensation and absorption.
Perhaps your fuel might have been contaminated with ethanol and now that the bike has sucked it through it will run better.

You can pull the fuel pump out of the tank,  if the tank is almost empty. Lay the bike on its side, with the pump on the top side, and undo the pump. Clean off the screen when you have it out.

[Guaire]

ChrisR - There's a fuel filter inside your gas tank. It's part of the fuel pump assembly. I needed to overhaul a fuel pump. I replaced the pump. I got a Quantum from an eBay seller. There's no need to replace the whole unit.... usually.
Cheers,
Bill G.

[Haggis]

The main pump mounted filter works down to 10 microns.
Smaller than the injector nozzle holes.
The injector also has a tiny filter at its input end.
Most fuel problems are electrical.
Get the relays changed and fit a new spark plug.

[ChrisR]

Thank you all for the advice! I'm in the UK and ethanol based fuel (E5 and E10) is now a thing here. I'm not sure what was in the fuel tank when I bought the bike late last year (a 2020 with only 500 miles) or even how old the fuel may have been... so I think replacing with fresh fuel and removing the pump beforehand for cleaning should remove one set of uncertainties at least. The replacement relays arrived today, so I'll be fitting those shortly. Thanks again for the advice and pointers all. Greatly appreciated! 

[ChrisR]

Just an update. I drained and replaced the fuel (but didn't take the pump out) I replaced both the relays and everything now appears to be running very nicely. Fingers crossed 

[oldphart]

Just an update. I drained and replaced the fuel (but didn't take the pump out) I replaced both the relays and everything now appears to be running very nicely. Fingers crossed 

Until you get 100 kms from town... 
Oh wait, you're in the UK, you can't get 100 kms from town    (no laughing smilie which would have been more appropriate)

[ChrisR]

Until you get 100 kms from town... 
Oh wait, you're in the UK, you can't get 100 kms from town    (no laughing smilie which would have been more appropriate)

  that's always a possibility! I'd have been a little happier if I could have tracked down for sure whatever the cause was. The old "scatter gun" approach will have to suffice for now