This is something I have had on numerous engines. After long usage, shut off engine, and just as the engine comes to rest, get a backfire. Is this normal, or is this an indication of something going wrong. I thought it might be a sign of tight valves, but I have checked the valves, and they are in tolerance......
I haven't been in the carb on this one. Its a Toro 522xi......I had a John Deere X320 before this, and both of them do it. Not all the time, but often, it will scare the crap out of yah, and the dog! I know what you are referring too, on the carb bowl. I have seen that valve thing, and always wondered what it was doing.....so that's supposed to prevent a backfire?
If it does have a solenoid on the bottom of the carb then there should be a set of wires that plug into it. To test if it working you unplug the wires to it while it’s running. If it shuts off the engine then it is working. If it keeps running then it’s not working.
Without knowing which engine you have I am just guessing. Kohler needs shutoff at near full throttle to prevent afterfire. Has to do with how the jets in the carb work. Others you idle down for a few seconds before shutoff. Even if everything is working correctly afterfire can still happen sometimes. Even the muffler can lead to afterfire.
#6
Its Me
let it idle down 30 seconds or so then kill it and it won't back fire, the exhaust if very hot when you cut the switch off it stroked a few time pulling some fuel in and the heat from the valve sets it off, no harm done, just a few seconds of Idle time will take care of it and keep you underwear clean.
