Walbro / Tillotson carb overhaul

Philmac wrote: Ok I’ll try some bigger files....

The instructions you've downloaded advise which gaskets to select . May be correct but based on karting experience.

For the main pump gasket it advises to select the tan (ptfe) which i agree with as they seem less likely to stick when the carb gets dry (Tillotson uses these by default )

I have no experience with the secondary device. so irrespective of karting experience, i still recommend like for like

suspect your carb might be Walbro WB series

FYI - this carb is obvious designed for the larger motors with higher fuel flows so has dual inlet check valves ( to allow better low pressure fuel flow) .
Have now studied the secondary device in the fuel chamber which is a high speed fuel jet check valve. Without this when the carb is in idle position, the idle jets would be able to draw air the wrong way from the high speed jet, vent fuel chamber and loose "suction" to open the fuel regulator.

So if the engine were to cut when returning to idle, or fails to draw fuel from the tank to start. this check valve would be a likely candidate.