Small Engines (Lawn Mowers, etc.): Dying Tecumseh 6.5HP Silver Series, mark magee, proper manuals

Question
I Have a Lawnboy self propelled 21" mower about 12 years old w/the Tecumseh 6.5 Silver Series engine, the engine is knocking badly on shutdown and won't turn off. I believe either the rod is knocking and or piston slapping. Either way I believe it's time for a new engine, can you provide a drop in replacement for this mower?
Thank You
Mark Magee

Answer
Hello Mark:

I Might be Able to. Send me the Model and Type Numbers Off the Engine and the Mower Model Numbers, Please. With these I can Locate the Proper Manuals and Better Assist you. BTW Have you Checked the Blade. On Some Model  Mowers, f the Blade Loosens it will Rock on Start Up and Shut Down and Make KNOCKing Noise. Thanks.

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 9pm EST (US). My New Day Starts then. Thanks.

Respectfully

John