Small Engines (Lawn Mowers, etc.): mower engine replacement, output shaft, connecting rod


Question
Mower: Lawnboy 10020 Silver Series, walk behind self-propelled with 4.5 HP Techumseh engine. Last week while mowing, the mower suddenly made an odd noise that sounded like something metallic tumbling around inside, then it stalled and wouldn't restart. Now when the starting rope is pulled, the motor is dead, but when the rope is released the blade can be heard spinning for a few seconds. I've been told this most likely is a thrown rod. What do you think?

I have several other mower engines from a 3.5 Tecumseh to a 4.5 HP B&S. They are from walk behind push mowers, not self-propelled as the Lawnboy. The mounting holes seem to be the same as the Lawnboy. Can I mount one of these on the lawnboy, or does the Lawnboy need a motor with a special shaft because it's self-propelled?

Answer
Hello Jerry:

From your Description, it Sounds like the Connecting Rod has Broken. Send me the Model Off the Mower, Please. With these I can Locate the Proper Manual and Better Assist you. However, if you want the Self Propelled to Function; you will Require an Engine with the Output Shaft for the Self Propelled.  You can Bolt Up the Other Engines if the Crankshaft Length is the Same as the Lawnboy Engine. You will have to Use the Blade and Blade Adapter that is with the Engine you are Replacing the Lawnboy Engine with. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

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