Small Engines (Lawn Mowers, etc.): Another stalling motor, float bowl, solenoid

Question
Hey John, I had the same prob as the last guy, took the flapper out of the cap and it ran great,mowing away, for about 20min-10 better than before.It wasnt angry it just purred on down to a stop Filter is new and was full of gas. This Sears model has a 18hp with a Nikki carb with a solenoid on the bottom of the float bowl. Since it seems the engine shut off when it was hot, do you think this could be the prob? I let it sit and its off to the races-for 20mins!!

Answer
Hello Jack:

If the Engine is Running Good for 15 to 20 Minutes, then Quits and Once the Engine Cools, it Starts Up and Runs Good for Another 12 to 20 Minutes and the Gas Cap is Venting the Tank, then the Problem is the Ign Module/Coil Heating Up and Not Firing the Plug/s Until it Cools. A Common Problem. Operate the Engine Until it Quits and then Immediately Check the Plug/s for Firing. If No Fire, then Replace the Ign Module/Coil. If the Plug/s are Firing, then Check the Carburetor Solenoid. If the Carburetor Shut Off Solenoid has Current, then Remove the Carburetor Solenoid and Go to the Hardware Store. Purchase a Bolt of the Same Diameter and Threads. It Needs to be 3/4" Long. Put this Bolt in Place of the Solenoid. If this Corrects the Engine Problem, then Replace the Solenoid. ***NOTE: THIS IS FOR CHECKING THE SOLENOID ONLY I NEVER SUGGEST YOU OPERATE THE ENGINE WITH THE SOLENOID OUT OF THE CARBURETOR EXCEPT FOR TESTING PURPOSES*** Sometimes the Plunger is Moving, Just Not Far Enough to Allow the Gas to Enter the Jets Properly. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John