jkz
New member
why does 16 h p briggs back fire after mowing ??? runs great..
zeke
- Thread starter jkz
- Start date
Welcome to the forum!
You mean it backfires once or twice when you shut it off? This is typical behavior for the Kohler twins and it's at least part of the reason why those have an "afterfire solenoid" that electrically cuts off fuel at the carb when the key is cut off. I don't know if the 16hp Briggs has this feature or not. If so, yours may not be working. You can usually hear it click right at the carb when the key is cut off/on. Check any electrical wiring right at the carb. Mine had the ground disconnected by a PO.
For some reason that I don't really understand, my mower/engine manufacturers (Cub/Kohler) are also very specific in the owner's manuals about the engine shutdown procedure -
Stopping
1. Remove the load by disengaging all PTO driven
attachments.
2. For Engines without a Shutdown Solenoid:
Move the throttle to the slow or low idle position.
Allow the engine to run at idle for 30-60 seconds;
then stop the engine.
For Engines Equipped with a Shutdown
Solenoid: Position the throttle control between
half and full throttle; then stop the engine.
You mean it backfires once or twice when you shut it off? This is typical behavior for the Kohler twins and it's at least part of the reason why those have an "afterfire solenoid" that electrically cuts off fuel at the carb when the key is cut off. I don't know if the 16hp Briggs has this feature or not. If so, yours may not be working. You can usually hear it click right at the carb when the key is cut off/on. Check any electrical wiring right at the carb. Mine had the ground disconnected by a PO.
For some reason that I don't really understand, my mower/engine manufacturers (Cub/Kohler) are also very specific in the owner's manuals about the engine shutdown procedure -
Stopping
1. Remove the load by disengaging all PTO driven
attachments.
2. For Engines without a Shutdown Solenoid:
Move the throttle to the slow or low idle position.
Allow the engine to run at idle for 30-60 seconds;
then stop the engine.
For Engines Equipped with a Shutdown
Solenoid: Position the throttle control between
half and full throttle; then stop the engine.
RPW
Veteran Member
- Joined
- Aug 12, 2009
- Messages
- 1,105
Generally you want to slow the motor down to idle or near idle and let it cool down a bit before shutting down. I have a Bobcat with a gas motor and if I don't let it idle down then it will backfire.
6Mickey
New member
Backfire is a misnomer! What you have described is a muffler explosion. When the ignition is turned off to stop the equipment, the momentum of the flywheel continues to 'spin down' and the fuel is still being passed through the combustion chamber and into the muffler. The vapors are unburned. When the crank shaft stops, the pumping stops, and in a short time the oxygen rich air flows into the muffler (backwards) and with the heat of the carbon in the muffler and the unburned gas vapor, bang! The explosion happens.
On the other hand, when a true backfire takes place, it is usually a timing issue where the fuel vapor going into the combustion chamber ignites in the intake and carb and bang! BTW, it happens in turbine engines on jets. (not good, sudden, explosive reversal of axial flow through the engine)
On the other hand, when a true backfire takes place, it is usually a timing issue where the fuel vapor going into the combustion chamber ignites in the intake and carb and bang! BTW, it happens in turbine engines on jets. (not good, sudden, explosive reversal of axial flow through the engine)
6Mickey
New member
Sorry Zeke, I am not aware, even, that Ryobi makes a 4 stroke weed wacker. If ignition timing seems off, look for a sheared flywheel key. Or if it really is a 4 stroke engine and you have it apart, are you talking about cam to crank timing? Sorry I cannont help.