QuestionMy MTD riding lawnmower with a B %26 S 14.5 HP engine has lost power and the muffler becomes red hot. There appears to be good muffler exit exhaust. Is it possible that a baffle in the muffler has come loose and is restricting the exhaust flow?
Answer
Broken
Ed
No this is a timing problem. Did you hit anything lately while cutting? You may not remember doing so. This would cause the flywheel shear key to break. Take the housing cover on top on the engine and see if the key way is aligned with the shaft. You may have to take off a few other items to see this. I have enclosed a picture for you as a example.The flywheel on your small engine was originally designed to store the momentum from combustion to keep the crankshaft turning in between the engine's power strokes.
Removing The Flywheel
Disconnect the spark plug lead and secure it away from the spark plug. Then, loosen the bolts holding the shroud in place and remove the shroud.
If the engine is equipped with a flywheel brake, remove any cover and disconnect the outer end of the brake spring.
If the flywheel is equipped with a flywheel clutch, remove it with a flywheel clutch tool while holding the flywheel with a flywheel holder or a flywheel strap wrench. If the flywheel is attached with a nut, use the flywheel holder as a brace, and remove the flywheel retaining nut with the appropriate socket.
With the flywheel nut threaded onto the crankshaft, install a flywheel puller so its bolts engage the holes adjacent to the flywheel's hub. If the holes are not threaded, use a self-tapping flywheel puller or tap the holes using a 1/4 X 20 tap.
CAUTION: Never strike the flywheel. Even a slightly damaged flywheel presents a safety hazard and must be replaced.
Rotate the puller nuts evenly until the flywheel pops free. Then, remove the flywheel and key.
Installing The Flywheel
First, obtain a new flywheel key designed for your make and model from your Briggs & Stratton Authorized Dealer.
Place the flywheel on the crankshaft and look through the flywheel hub to align the keyways on the flywheel and crankshaft.
With the flywheel in place, place the key in the keyway; it should fit securely. If you feel play, check to see if the key is upside down. Debris can also prevent the key from seating in the keyway.
Once the key and flywheel are securely in place, reattach the flywheel nut or clutch. Consult your Authorized Dealer for the torque specifications for your make and model.
