I have a 2001 ttr225 and I am completely stumped. I was having oil burning issues so I decided to investigate. I pulled the cylinder off and found a trashed piston and rings. I replaced them and the piston pin and all the gaskets I took off. Got it all back together and it fired up on the first turn off the starter. Ran really strong and no oil burning. After about 8 seconds the bike shut down and made a single click. I investigated and realized that I forgot to tighten the cam shaft gear to the proper torque. It came off. I got the timing chain back in place and the engine back together but now it will not start. The starter motor engages and turns but it won't fire. I have spark, and a new plug. The carb was cleaned and got new jets 2 weeks ago and worked great before the new piston. I quadruple checked that everything lines up at tdc. I turned the fly wheel with a wrench and the valve covers off. It all seems to be operating correctly and the valves engage fully. The valves are adjusted to the spec in the manual. I sprayed starter fluid in the spark plug hole and put the plug back in, it did not fire. I'm about at the end of my rope with this thing. Any help is greatly appreciated.