2010 Husaberg FE390 subframe tank problems

try to separate failure origins.
- any of the fuel filters full of debris
- injector still working properly
- are grounding connections (battery’-‘) making good contact
- ignition still working properly (electrical contact, timing)
- does the tank stil allow for enough air intake
- are the fuel lines running free; no kinks, no heat build up
- is wiring seated properly and still well insulated
And probably other possible causes should be checked too.

Filters

The usual suspect is the small, ~13mm long conical filter in the black fitting that is screwed to the throttle body on the left side, that the fuel line is fitted to. Take off the fuel line, undo clamp on line, pull off line, filter will usually fall out or be stuck in the black fitting. Replace, it's the same as all later '12 on KTM Husky etc that fits in the fuel line quick connect. Or blow out backwards with air or contact cleaner at least. Then the big 50mm long cylindrical Mahle branded filter in the tank on the fuel pump output line, and also screen on the bottom of the fuel pump that can be removed and blown clean. Also screen on the injector- you need to remove injector, open with 5 volts, spray clean with injector cleaner.
Whatever anybody else says, I DO NOT agree with removing small filter.
Profill in Australia makes a great fabric filter for the tank filler and the fuel pump that I thoroughly recommend, they will solve most problems with dirty fuel.