Small Engines (Lawn Mowers, etc.): B&S 15.5 HP OHV Engine Red Hot exhaust, ohv engine, exhaust pipe

Question
I just replaced the flywheel gear ring on this engine, when I started it up, it sounded strange. Like it was running rough. After a few minutes I noticed the exhaust pipe was glowing orange and flames were coming from the muffler. What can be causing this?

Answer
Hi George,
When you tightened the nut or bolt (depending on the code) that holds the flywheel on, did you get it REALLY tight? If it's not really, really tight, it will shear the flywheel key. It sounds like that's whats happened. Take the flywheel back off and check the key. Let me know if this was the problem of not.
Thanks,
Keith