Craftsman LT2000 riding mower was running great until I hit a cut down tree stump. The blade instantly stopped, then the engine shuddered and died. A puff of black smoke came out as it died. There was a strong smell of fuel. We immediately put everything into the OFF positions and lifted the deck and mower off the stump. General visual inspection of the deck, blades, and engine with shroud on appeared ok. Blades rotated ok by hand. Tried to start it. Engine turns, but won't kick on. The turn over sounds different than before. Almost smoother or easier? Like something that was happening before isn't now. While trying to start it, I noticed a heavy fuel smell. We tried to put it in neutral and push it to the garage. It was rolling fine. I decided to try to start it one more time. Same thing. Tried to push it the rest of the way in neutral, but the brakes locked up. So we left it there overnight. I tried to start it again this morning. Same thing. I tried changing the shifter positions a few times, tried engaging/disengaging the parking brake several times, tried rocking the mower back and forth... can't get the brakes unlocked. So I'm left with two problems. Riding mower won't start and brakes locked up. Any suggestions for fixing these two problems? Thanks!

-- update 3/8/18 --

I've been troubleshooting. I checked the ignition coil and spark plug wire with a spark tester. Spark was steady flashing and consistent. Checked the spark plug via arch test. It didn't have much of a spark, but it did spark. Even with a new plug. No change. I'm going to charge the battery tomorrow just in case there isn't enough battery power.

I took the engine shroud and flywheel cover off. Did a visual inspection of the flywheel key (only from the top). It looked ok.

I sprayed some carburetor fluid into the air intake and tried to start it. It did not combust. No change.

I'm also going to test the fuel lines before and after the fuel filter tomorrow to see if the filter is plugged up.

Compression was going to be my next check. Fun times. Sigh.

-- FINAL UPDATE and SOLUTION --

After taking the engine apart, I immediately saw that the camshaft AND the timing gear had both broken (shattered into pieces). The flywheel key did absolutely nothing to prevent that and was completely untouched. I replaced the broken parts and installed new engine gaskets, seal, oil and fuel filter. Problem solved.

I bought all genuine Briggs & Stratton parts from Amazon. They had the best pricing and shipped the fastest. I haven't had any problems with the parts either. The pricing can change and may also vary depending on if you are an Amazon Prime member (I am), so I will just share the links to what I bought.

You may not necessarily need all of this stuff, but I did for this repair. These parts are specifically for the Craftsman LT2000 with the Briggs & Stratton engine.

Briggs & Stratton Camshaft - https://amzn.to/2XiuCTj

B&S Timing Gear - https://amzn.to/2MMVSFm

B&S Timing Key/Flywheel Key/Shear Key - https://amzn.to/2ILa9NE

Briggs & Stratton Oil - https://amzn.to/31xAeIz

B&S Engine Gasket Set - https://amzn.to/2Khph8q

B&S Oil Seal - https://amzn.to/31wiCN6

B&S Oil Filter - https://amzn.to/2XcjOG3

B&S Fuel Filter - https://amzn.to/2MLhmCs

LOCTITE Blue - https://amzn.to/2IJ6NL3

Permadex Engine Assembly Lube - https://amzn.to/31yyL4q

Silver Anti-Seize - https://amzn.to/2N0Z2Wf

Carb/Parts Cleaner - https://amzn.to/2MLq2sw

Feeler Guage - https://amzn.to/2MNdJMr

Small Torque Wrench - https://amzn.to/2KgFJ99

I already had a large torque wrench and other hand tools which was needed as well.