I have a Troy Bilt 21" mower 11A 542Q711 with Honda engine. A basic rotary mower from Home Depot. It's a newer machine that has always started instantly and run great. Today I was mowing and bumped the front of the mower into a deck structure. The mower immediately quit and wont start. The 'bump' may have jarred the spark plug and wire. No visible damage. I changed the spark plug and still no start.
The air filter and carb look clean. Plenty of fresh gas. My gut tells me there's no spark or ignition. What do I check next? Try a new magneto?
Thanks!

 

Hello senor-mouse,

Since your machine stopped immediately following hitting the deck, Take a look at the valve cover in the yellow box below. If the hit was hard enough to bend the cover in it will keep the valves from closing, Thus shutting the engine down.





If you find the cover bent in, It can be removed and tapped back out to allow the rockers to move fully again and valves to close.


Good Luck

 

1. Did the mower make a clang sound or did it sound like the blade hit something causing it to suddenly stop? If so it possibly sheared the key between the flywheel and crank shaft. It's a $.29 part that helps set the timing of the engine and if it sheered the ignition's timing will be off, which will prevent the engine from running.

2. Remove the spark plug and re-attach the wire to it. Touch the tip to a bare metal part of the engine. Pull the starter cord like you are starting the engine. Do you see the plug sparking? If you see a spark you have confirmed that the coil, spark plug wire and spark plug are working.

 

Pretty good chance 31YTech is on the money. The valve cover on these is super thin and easy to bend. This will cause it to shut down immediately.

 

Great suggestions! Yes, the valve cover got dented. I actually took the bolts off but it's stuck on (probably a gasket sealer from the factory) so I didn't proceed further. I'll try this repair today and report back.
Thank you!

 

Mower is fixed! It was the dented valve cover. Thanks for the help.

 

Good to hear you got it straightened out. [ATTACH=CONFIG]460[/ATTACH]