DYT 4000 Acting Strange

[Dr. Internet]

I have owned my Craftsman DYT 4000, 18.5 hp Briggs since 1996. during that time I have repaired or replaced most everything, except the steering wheel.
It sat last summer due to the heat and drought. Inspected it before use and bought new blades, spindles, bolts and belts. Got a new battery, new carb and found a fuel leak in the rear. Fuel line broken where it enters the tank. Replaced fuel line and installed new fuel filter. Put in better fuel cut-off switch, new fuel lines everywhere. New filters. Changed oil and plug.
Started up right away. Ran as good as new for about 1.5 hours, then started backfiring. Complete lack of power, would not even turn the blades. Limped back to the patio (i.e. workshop). Next morning, same thing. Ran great for about 1.5 hours, then no more.
It looks like it is getting enough fuel, but I ordered a new fuel pump.
It is not burning oil or blowing any smoke when it fails. Just a lot of backfiring and jumping around.
Any thoughts would be appreciated.
Thanks!

 

[ILENGINE]

Get a couple of the blink type spark testers and pop onto the spark plug leads and go mower and when it starts acting up make sure both plugs are sparking regularly and not misfiring. It gives a hint that one of the ignition modules is breaking down due to heat.

 

[Dr. Internet]

Get a couple of the blink type spark testers and pop onto the spark plug leads and go mower and when it starts acting up make sure both plugs are sparking regularly and not misfiring. It gives a hint that one of the ignition modules is breaking down due to heat.

Thanks for your reply.
This is an old 18.5 hp Briggs. One cylinder, no ignition module. Just an Armature-Magneto. I will get the spark tester and see if the insulation is breaking down due to heat.
Thanks again!

 

[Dr. Internet]

IL Engine,

Man, you nailed it! Took things apart and discovered that the armature was actually touching the magnet on the flywheel. Found an old business card, adjusted things, and she ran for two hours with no problems.
Thanks a million, man!

 

[ILENGINE]

Thats for letting us know what the fix was.