I have an X300 that I purchased new in 2006/7. It starts up fine and I can mow for ~20mins before it starts to stall. If I disengage the blades, the engine stabilizes and will remain running. Re-engaging the blades will cause the engine to stall again. After letting it cool for 10mins, I can restart it and mow for a few minutes before it stalls again.
I have cleaned the vented gas cap and even ran it without a gas cap but this had no effect.
I have not been running it on ethanol-free gas. But for 12 years I haven't been and never had an issue.
During the stall, the amount of gas visible in the clear plastic fuel filter is normal.
Any help would be greatly appreciated.
Stalling X300 - YouTube