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View Full Version : Lawn Tractor will not start, Briggs&Stratton 18.5hp engine


rcuster2
Aug 8, 2008, 05:42 AM
I have a 2 and 1/2 year old Craftsman Lawn Tractor with 18.5 Briggs & Stratton Engine (31P777-0348-E1). I has been serviced each year prior to use. Have been using all season with no visible problems. After starting the engine and ridng for about 2 minutes, the engine stopped. There is no noise or smoke from the engine but it will not crank and only move approx. 3" when you try to manually turn the fly wheel. The oil level remains at full level. Any suggestions? Thanks

John C Bridgers
Nov 5, 2008, 04:29 AM
Hello rcuster2:

From your Description it Sounds like the Valve Clearance Requires Adjusting. The Following is a Basic File I made for Setting the Valve Clearances. Any Input is Appreciated. **I Do Not Use the Setting Called for by the OEMs. I have Found that the Following Works Best. Remove the Valve Cover (on the Dead Cylinder for Twin Cylinder Engines). Set the Cylinder you are Setting the Valves on to Top Dead Center on the Compression Stroke When Setting the Valve Clearance. Now Loosen the Valve Adjuster Locks and Using a Blade Style Feeler Gauge, Set the Intake Valve Clearance to .004in -.006in and the Exhaust to .007in - .009in. I have had Better Performance Out of the Mowers and Less Burnt Valves Using these Settings. Be Sure the Piston is at TDC on the Compression Stroke.** If you Remove the Valve Cover and then Turn the Engine by Hand, you can Watch the Intake Valve Movement. When the Intake Valve Closes, the Piston will Just Starting the Compression/Power Stroke. On Some Engines you can Us a Straightened Coat Hanger and Feel the Piston. Be Careful and Don't Jam the Wire in the Cylinder. Usually the Piston will Push the Wire Out of the Spark Plug Hole with No Problems. 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. Thanks.

Good Luck

Respectfully

John

EWJ
Nov 25, 2008, 12:03 PM
My MTD Yard Machine 13.5 HP lawn tractor will not start; just clicks. I've replaced the battery, but that wasn't the problem. I can remove the module from the inside of the ignition, but cannot pull the keyhole part of the switch out. What's holding it in?
Thought the switch might be the problem.

JEPLAX
Aug 8, 2009, 07:09 PM
I wa having a similar problem with my craftsman lawn tractor with a B&S 18.5 hP OHV, Inteck engine last summer. I thought I had a clog in the fuel line or fuel filter & blew out the line & changed the filter. Then I discovered that dirt was clogging the air hole on the gas tank cap, so a suction was created and gas was not able to reach the carb. Now I tighten the gas cap and turn back 1/2 turn so air can enter the tank. This stopped the problem. It the other approach does not work, try this one.