2006 TTR 125...sat for 2 yrs. Tried to start it...no joy. Pulled and cleaned carb, changed plug, she started just fine. Ran it for 2 hours, normal shutdown. Went to start it an hour or so later, nothing. After 10 kicks, backfired through carb. Any thoughts?

Remove the gas tank shut off valve and clean it or replace it. The filter in it must be clogged.

When you cleaned the carb, did you remove ALL of the jets and make sure you can see light through them? Also, some pilot jets have holes on the sides that plug up and are almost invisible. Look closely, and spray carb cleaner through all passages and make sure it comes out somewhere else.
Good Luck!

Drain out old fuel.put in fresh fuel. Take out spark plug put in little gas and put spark plug back in. try to start.

It has to be in kill switch replace it and see

buddy change the plug also on the carb there will be a idle screw turn this in 1/4 of a turn with the machine running and get back to me

Your bike has a diaphragm on the carb. Every time you twist the throttle a shot of gas goes into the cylinder. Chances are you are flooding the engine by twisting the throttle too often. Flooding can create a backfire. Start with a clean dry plug. Twist the throttle once then leave it alone for about six kicks. Repeat the process if needed.

check the gap in your shims.it sounds like you have got a valve stuck open.

Check the rectifier.

this is very tipical. when bikes are stored the fuel varishes up the jets & needles. soak the carb. moving it back and forth in the soak solution. then blow every jet and orfice with a controlled air source. note: any speck of rust or dirt can plug these jets. pay attention to detail and do every thing twice. then install the carb and adjust it to your riding style. later Spike