QuestionMy Snapper riding mower turns over, but wont start. Checked all electrical wires, appear OK. Put in new ignition module. Briggs 121602-0175E1. Engine compression is 60. Getting weak current when using inline tester from plug to ignition module. Would a partially sheared flywheel key produce a weak current to plug? Any other suggestion of why it will not start?
AnswerHello Tony:
>>You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model (5 or 6 Digits) and Type Numbers (first 4 digits Only). Example: 121602-0175-E1. Then Double Click on the Model in the Results Area. Select Sectional Index. Now you can Select the Section of the Engine you Wish to View.
>>I See this is an OHV Engine.
>>Is the Engine Turning Correctly when Trying to Start it or is it Dragging/Slowing at the Same Point During the Starting Cycle?
>>If Yes, then Set the Valve Clearances.
>>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 Lock and Using a Blade Style Feeler Gauge, Set the Intake Valve Clearance to .004in -.006in and the Exhaust to .004in - .006in. Loosen and Tighten the Rocker Arm and the Feeler Gauge is Placed Between the Rocker Arm and the Valve Top where the Rocker Arm Pushes on the Valve.
>>***BE SURE TO TIGHTEN THE ADJUSTER LOCK AFTER YOU HAVE THE PROPER VALVE CLEARANCE***
>>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.
>>A Damaged Flywheel Key Causes the Plug to Fire "Out of Time" with the Piston Locating During the Power/Compression Stroke.
>>The Following is the Instruction File I Made for Removing the Flywheel from Most Mower Engines. It is the Basics and if you have a Question, Please Ask. Any Input to Make this File Better is Appreciated. ***Disconnect the Coil Wire from the Spark Plug. Remove the Blower Housing (metal engine cover). Remove the Coil. Remove the Flywheel Nut or Starter Cup (Depends on the Model). Now Attach a Steering Wheel Puller to the Flywheel Using the Threaded Holes in the Flywheel. Tighten the Puller. Now Hit the Puller with a Hammer. Repeat this Procedure Until the Flywheel Pops Up or can be Lifted Off the Crankshaft. On Some Models you Can Not Use a Puller and and the Jaws of a Standard Puller will Not Fit. On these Type Engines you can Use a Pry Bar and a Pipe Cap that is Slightly Larger than the Crankshaft. Place the Pipe Cap Over the Crankshaft to Protect it. Place the Pry Bar Under the Thick Section of the Flywheel and Pull Up Against the Flywheel. **BE CAREFUL DO NOT PUT A HOLE IN THE BLOCK UNDER THE FLYWHEEL** Now Hit the Pipe Cap that is on the Crankshaft (covered with the Pipe Cap). Repeat the Procedure Until the Flywheel can be Lifted Off the Crankshaft. *** Be Sure you have the Flywheel Torqued to the Proper Torque (I require the Model and Spec/Type Numbers Off the Engine to Provide the Proper Torque) and Set the Coil Gap to .020in..
>>Here is a Basic Instruction File I am in the Process of Making. It will Might Say Mower, but a Snow Thrower/Blower is Powered by the Same Type of Engine, so the Diagnostics are Basically the Same. >>***Here are some Diagnostic Instructions to Do on the Engine to Locate the Cause/Cure for a Hard/Not Starting Engine. This Does Not Include a Problem with the Valves. If I Suspected the Valves are Involved, then a Separate File for the Valves will be in this E-mail. This is a File in the Making, so Any Input is Appreciated.
>>1- Check the Spark. If Not Firing, then Replace the Plug.
>>2- If the Plug is Firing, then First, Pour a Small Amount of Gas (1oz) Into the Carburetor Throat with the Throttle at Full. With the Throttle Still at Full, Try to Start the Engine. If the Engine Starts and Quits, then Make Sure the Gas is Free Flowing to the Carburetor. If the Gas is Free Flowing, 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, Float Pin, Float 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. Install New Parts if Required.
>>3- If No Fire at the Plug, then Remove the Coil Shut Off Wire from the Kill Switch at the Engine Stop/Brake Bracket (where the End of the Stop/Brake Cable Attaches at the Engine). Check for Fire. If No Fire, then Remove the Blower Housing and Remove the Ground Wire from the Coil. Check for Fire. If Still No Fire, then the Coil is Bad. *On Some JD Model Mower the Engines Use an Igniter. Remove the Igniter and Coil and have your Local JD Dealer Test them for you.
>>* **On Models with Point Set, the Condenser is Bad and the Point Set and Condenser should be Replaced as a Unit. Make Sure the Point Set Plunger is Fully Extended when Setting the Point Set Gap to .020in.
>>** If there was No Response from the Engine When the Gas was Poured Into the Carburetor Throat and the Plug was Firing, then Check the Compression. If the Compression is Good, the Carburetor has Been Soaked and Cleaned and the Plug is Firing, then Check the Flywheel Key. If the Key is Damaged, then the Plug Firing is Incorrect to the Position of the Piston During the Compression (Power Stroke).
>>*** On the OHV and Some L-Head (Flat Head) Engines there is a Compression Release. The Exhaust Valve Clearance has to be Opened to .020in for the Compression Release Not to Operate; in Order to get a Correct Compression Reading.***
>>Please, Do Not Hesitate, If you Hit a Snag, if I Missed Something 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. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
