My sons 2021 KFX 90 isn’t getting fuel. I replaced the filter, pulled and cleaned the carb and all of its parts and even pulled and cleaned the petcock.

Fuel flows freely from both lines from the tank to the petcock, (reserve and on). Coming out of the petcock however the “on” position fuel is only dribbling out. When on Reserve fuel flows unobstructed.

the fuel filter doesn’t appear to filling up, even when on reserve.

the bike will start but won’t stay running as it stalls out when it gets the remaining fuel from the bowl. I took the line from the carb off and tried drawing fuel through the line with my mouth but no luck.

Any advice?

 

Depending on how they are positioned, fuel filters don't always fill right up as air trapped in them can't get out unless the filter is vertical. If it is paper element, the filter can air lock too, if drained of fuel. Before new fuel can get to it, the air in the filter has to pass through it, and air doesn't go through a wet paper element easily. I put some pressure on by blowing down the tank vent, once the fresh fuel gets to it, the filter will start working again. Regarding the tap, check if the fuel flows freely from it with it disconnected from the filter. If so, either the filter is air locked, or blocked and you need another new one. If the tap still just dribbles in the on position, with the filter disconnected, you haven't cleaned the tap out properly, try again.