Sometimes when your dirt bike does not get used, it won't start.
Here are some ways to start a "mad motor."
Step 1: Follow These Steps to Get Your "Mad Motor" Running
1. Make sure the gas line is ON.
2. Make sure you have gas in the dirt bike.
3. Make sure the spark plug boot is pushed in.
4. Make sure you have spark. To test for spark, take the spark plug out from the head, but not out of the boot. Put it against some metal on the bike and turn it over while kicking the kick start (or if you have an electric start, use that). You should see spark. If you see no spark, then put a new spark plug in. Make sure to put the right size spark plug in and do not over-tighten the spark plug.
5. Use choke.
6. If the motor has not run in a long time (i.e. more than 1 year), you should put new gas in it.
7. Once you have done all of these steps and it still won't start, then clean the carbs.
8. Clean the air filter.