Engine kills after 5 minutes

[blue262]

I just bought a Snapper ST140, model 3312513BE with a B&S 12.5hp, model 286707-0136. I bought it cheap for a project. It starts and runs for about 5 minutes and then kills. The previous owner replaced the carburetor and the armature with no change in performance . The plug is fouled with black soot. Just turning the flywheel by hand I think the compression may not be and issue. I would appreciate any thoughts on what things I should check next.

 

[Tiger Small Engine]

I just bought a Snapper ST140, model 3312513BE with a B&S 12.5hp, model 286707-0136. I bought it cheap for a project. It starts and runs for about 5 minutes and then kills. The previous owner replaced the carburetor and the armature with no change in performance . The plug is fouled with black soot. Just turning the flywheel by hand I think the compression may not be and issue. I would appreciate any thoughts on what things I should check next.

Take gas cap and make it loose (tape it), and run it. Also. Remove fuel line and check for good fuel flow.

 

[Rivets]

Buy an inline spark tester at an auto parts store and the next time it happens install the tester and check for spark. No spark bad coil, spark fuel problem.