Small Engines (Lawn Mowers, etc.): Sears Garden Tractor Model 917273061, internal passages, electric clutch

Question
I am having problems. Once I start the engine it will run and the mower will engage for approx 3 to 4 minutes then it will die unless I engage the brake/clutch.If I release the brake it will die unless I re engage the clutch.
Over the past several weeks I have replaced the electric clutch, PTO switch, relay asm.,both ignition modules. I read in one of your eariler answers to jump the safety switch under the seat. I have just tried that and same thing is still happening. Any Idea's for me.
The engine is a kohler cv20s, type 65551. Thanks for your time.

Answer
Hello Tom:

The Statement "Runs for 3 to 4 Minutes" is a Give Away. It Sounds like the Carburetor Needle Valve is Stuck and is Restricting the Gas Flow Into the Carburetor Bowl. I Suggest you Check/Clean the Carburetor and Make Sure the Inlet Port is Clear and the Gas is Free Flowing Into the Carburetor Bowl. The Extra Load on the Engine Draws More Gas from the Bowl and if the Needle Valve Does Not Open Fully, then the Gas in the Bowl can Not Keep up with the Amount of Gas Used by the Engine and the Engine Stalls Unless you Remove the Load and the the Engine can Run because the Needle Valve is Open Just Enough to allow enough Gas in to Run the Engine without a Load.  Even though the Carburetor Looks Clean, the Internal Passages May be Restricted with Varnish that Gas Causes to Build Up over Time. I Suggest you Make Sure the Gas is Free Flowing to the Carburetor Inlet Port. If the Gas is Free Flowing to the Inlet Port, then  **Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk). I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning. You Only have to Remove the Bowl (if Applicable), Float Pin (if Applicable), Float (if Applicable)  and Needle Valve and Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed. Then Soak the Carburetor Body and Parts in a 1 Gallon Can of Gunk Carburetor Cleaner Overnight. The Can has a Parts Tray Inside it for the Small Parts. Once the Carburetor and Parts are in the Cleaner, you can Replace the Lid for Safety and to Prevent Accidental Spillage. Then Blow Out the Passages with Compressed Air.*** (Do Not Use High Pressure Air for the Zama Carburetors, they have Check Valves for the Primer and these are Usually Blown Out of the Carburetor if Not Careful. Allow the Zama Carburetor to Set on a Drip Pan and Dry)***. Install New Parts if Required.** To View a Breakdown of this Unit Go to this Site Addy, http://www.searspartsdirect.com/partsdirect/index.action and Enter the Model Numbers and Click Search. From this Page you can View Diagrams and Parts Lists for you Equipment Using the "View Sub Components" Section. You can View a Breakdown of the Engine at this Site Addy; http://www.kohlerplus.com/login.asp and Select Enter as Guest. Now Select the Thumbnail of the Engine Catalog you Wish to View. 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