So the 312R has been sitting in the corner with an N95 mask on like so many of us for a couple of years now. A brief turn of the key revealed a lack of any usual sounds so a quick prod of the wires pointed to a fuel pump issue. After a little investigation the tank was pulled to discover this little shop of horrors. It looks like ethanol has actually turned the immersed fuel lines into a substance resembling jellied snot.
Even the in tank filter has crapped itself in a bad way.
The really worrying part is the bike was only ever filled with premium fuel so must have got a bad tank full somewhere.
The IOM is high on the list of suspects but I’m fairly sure that would have been washed out before resting up.
Either way if you’ve got an F4 stored my suggestion is to add fuel stabilisers and run it for a while then drain the tank just to be sure.
Some J30R10 Gates hosing has turned up and will be fitted with a fresh KL145 Mahle filter and a new pump screen.
Hope your milage varies from this but if you have a stored F4 maybe just smell the fuel and if it reeks of white spirit get the cheque book out pronto.