F-20: 10-16hp Kohler 20 lbs 
$141.75
Briggs Vanguard Adjustable Steel Flywheel comes complete with magnet.     $375.00 1 Cylinder Kohler Magnum Steel Flywheel for ring gear   $190.00 Does not include magnet, use one off of stock flywheel
F-19: 10-16hp Kohler For Ring Gear 19lbs  $157.50 F-25: 10-16hp Kohler For Ring Gear 25lbs  $178.50 FC:  Command Flywheel-Adjustable Timing 23 lbs  $275.00

New Briggs & Stratton Vanguard V-Twin
starter ring gear $60.00

 

Lightened Steel Flywheel weighs 10 Lbs.  Made to fit starter ring gear.   $240.00