'05 TC-450 decided not to start after a great ride in the woods. Left me walking 3 miles pushing.

Hello everybody, I have had my '05 Husky for about 4 years now with very little trouble. While out riding in the woods two weekends ago I decided to pull off the trail and take a break for some water. Sat for about 10 minutes, then went to restart and she wouldn't fire. After pushing the bike for over 2 miles, I finally got back to the trail head and loaded up. Once home I started troubleshooting. The starter is working good, everything sounds normal... Once the engine gets to its normal place to start up in its cycle, the starter sounds like its almost moving a bit too fast, and the engine never does start up. Not a backfire, pop, or snort at all, but the exhaust is getting warm. I have taken everything apart and cleaned it with the exception of the electrical wiring and the bottom end. Carb looks good, plug is sparking good and has okay gap. I even took the starter motor out and everything looks good there. Removed cover from top end as I thought maybe a valve was stuck open or spring broken, but it all checks out. I have good compression also... Any ideas on what could be causing this? Is it possible that the timing is off on the bottom end somehow? I verified good timing on the top end. Any thoughts or help is appreciated!

How can the exhaust get warm if the bike is not starting?

Well, basically it needs air, fuel and spark to run. If you've got those and it still won't start then you have other issues like timing, valves or you left the wash plug in...oh wait, that's me

I would replace the spark plug, sometimes they will spark when out of the engine but not spark under compression.

will happen with weak spark in general too

Sounds like your valves are tight or decomp problem.

I'm going to check valves also, maybe I just need to re-shim? I will let you all know.