Small Engines (Lawn Mowers, etc.): Briggs & Stratton 15.5 hp rider mower engine problem, twin cylinder engines, briggs stratton

Question
I Have a sears rider mower with the Briggs 15.5 hp OHV IC platinum engine, model 28N707 type 0173-01, about 10 yrs old. I had replaced the flywheel gear ring, as the original plastic one had some teeth sheared off and the starter wouldn't spin it enough to start. The magneto was also replaced while the flywheel was off. After re-assembly, it seemed the starter was going, as the engine would stop, then spin up when cranked. It turns out the starter is fine (that was replaced), it's having a hard time turning the motor, which explains why the original gear ring teeth were damaged. I should note also that the engine ran poorly (loss of power) just immediately prior to replacing the gear ring.  It's always ran well, had proper level of oil, etc. but I'm wondering if there are some internal engine problems going on here. Appreciate the help.

Answer
Hello Edward:

This is Usually a Sign that the Valve Clearance Requires Setting. This is a Problem I am Seeing More and More with the OHV Engines. When the Valve Clearance get Off, it Causes the Compression Release to be Out of Adjustment and Causes High Compression During Start up. This High Compression has had Many People Replacing Starter that were Good and as you Found Out it Tends to Damage the Flywheel Starter Ring. 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 (28N707) and Type Numbers (0173) in the Appropriate Boxes and Click GO. Then Select Download PDF. **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 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 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

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Respectfully

John