Spits sputters and backfires

The first thing that you can check is the fuel pump, wiring and fuel filter. The power wires coming from the ignition, sometimes get corroded. the symptoms sounds like fuel starvation.

idle air control valve probably not working to supply enough air for idle speed during start up

If you have not replaced plugs start there A bad map sensor will also cause black smoke and poor running

Put a spike air filter on my 06 honda shadow spirit 750cc and now it spits and sputters won't go past 35 with out spitting and sputtering

Check for fuel supply problems as it sounds that at sustained high speed the fuel supply is not good enough. Possible pump dosen't have enough capacity

Check that the connection of the wires in the block connector (near the fuel tap) from the generator to the main loom is good. When checking the the ignition timing an ohm meter is connected to the black wire at this connector, sometimes causing the wire to 'pop' out of it's location and causing intermittent/complete ignition failure.

Did you hit something hard with your mower; like a stump or a rock? It sounds like your timing may be off. There is a key under the flywheel that is designed to break off if you hit something so that it doesn't bend the crank shaft on your mower. If that key breaks off, your mower will go out of timing and spit, sputter and backfire when you try to start it. Best of luck to you.
James

It certainly won't hurt. Also, check the timing.

when it hit 60/70 miles it spit sputters somtimes i change plugs , wires, cap still does the same
can you tell me what i need to look for.


thanks G man

not positive but in the air breather there is a mass air flow sensor and sometimes air filter particles gets stuck on the sensor.It will look like a white piece of lint,if there is be careful to remove it and try it.Usually a backfire and sputtering is the signs