Small Engines (Lawn Mowers, etc.): model 122782 briggs & stratton, valve spring compressor, briggs stratton engine

Question
Hi John:

I have a briggs & stratton engine model 122782, type 312401 code
90090456

I have spark & fuel but when I try to start the engine It seems to have a
popping noise coming from what seems to be the carb.  Is there a way to see
if the valves are hanging up without taking the cylinder head off?

Thank You

Mike

Answer
Hello Mike:

If the Flywheel Key is Not Damaged, then you Need to Check the Valve Clearance. Use the Following Instruction File to Check the Valve Clearance or Re-Set the Valve Clearance. If the Clearance is Good, then Most likely the Intake Valve Requires Reseating. The Following is a General Instruction File for Setting the Valve Clearance on Non OHV Engines. Any Input is Appreciated. **Remove the Carburetor and the Crankcase Breather/Vent and the Valve (Stem) Cover so you have Access to the Valve Stems, Springs and Keepers. Set 1 Cylinder to TDC on the Compression Stroke. Using a Blade Style Feeler Gauge, Check the Clearances. The Intake should be .005in - .007in and Exhaust .007in - .009in. If the Feeler Gauge will Not Slide Between the Valve Tip and the Tappet, then you Must Reset the Clearances. **You Will Require a Small Engine Valve Spring Compressor to Remove the Springs and Keepers from the Valve Stems.** Some Engines Use a Valve Keeper that is like Automotive Keepers (2 Cone Shaped Keepers that Set in the Valve Retainer/Rotocoil Assembly)and the Other Style is a Slotted Retainer that is Moved (once the Valve Spring is Compressed) to the Larger Opening in the Retainer and the Retainer Slips Over the Valve Stem Tip for the Valve to be Removed. Remove the Heads. Set 1 Cylinder so the Piston is at TDC on the Compression Stroke And Check the Clearances Between the Valve Stem Tip and the Tappet. The Clearances are as Follows: Intake Valve Clearance is .004in - .006in and the Exhaust is .007in - .009in. You have to Lightly Grind the Valve Stem Tip and Place the Valve Back Into the Engine (you can Hold the Valve Seated by Hand) and Check the Clearance Until you Reach the Required Clearances. Once the Valve Clearances are Reached, Re-Install the Valves on that Cylinder and Turn the Other Cylinder to TDC on the Compression Stroke and Set that Cylinders Valve Clearances.  Once that Cylinder is Set, then Re-Assemble the Engine.** If the Valve Clearance is Good, then the Head has to be Removed and the Intake Valve Removed and Reseated. I Suggest you Re-Seat and Re-Gap Both Valves if you have to Remove the Cylinder Head. You can View a Breakdown/IPL of the Engine at this Site Addy; http://www.briggsandstratton.com/maint_repair/manual_and_more/doclist.aspx?categ... and Enter the Model Numbers (XXXXXX) and the First 4 Type Numbers (XXXX) in the Appropriate Boxes and Click GO. Then Select Download PDF. 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