Small Engines (Lawn Mowers, etc.): masport mower briggs and stratton 4stroke, masport mower, briggs and stratton


Question
i have a 90s model masport with a 635 craftsman briggs and stratton 4 stroke engine that wont start

Answer
Hello Steve:

>>Sorry for the Delay. This Question was Located in the Question Pool and I can Only Answer Questions from the Question Pool when I am Not Answering Questions here or at the Other Site I Answer Questions at.
>>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 Welsh 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.***
>>Send me the Model and Type or Spec Numbers Off the Unit, Please. With these I can Locate the Proper Manual and Better Assist you. The Model Numbers May be Stamped Into the Blower Housing (metal engine cover) Above the Spark Plug. Many horizontal shaft, overhead valve engines have these numbers stamped into the OHV rocker cover. However, on certain overhead valve powered generators, the equipment manufacturer installs a decorative chrome rocker cover OVER the Briggs cover. If your engine has a decorative cover, it may be necessary to remove it in order to locate the Model, Type, and Code. If this is a Briggs and Stratton  Engine, then you can Also Use this Site Addy; http://www.briggsandstratton.com/maint_repair/BS_modeltypecode.pdf for Assistance in Locating the Model, Type and Code Numbers of a Briggs and Stratton Engine.
>>If you Hit a Snag or this Does Not Correct the Problem,  I Hope to be Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 5 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