>>166171If it's jetted right (pilot jet, needle, and air screw) it should still start with the idle screw set wrong. It'll either idle high, or won't stay running unless you've got the throttle cracked.
The basics are air, fuel, and spark.
Air filter/intakes - clogged? Packed with snow on a snowmobile, dirty air filter on a motorcycle, or a mouse nest in an engine that's been sitting for a while?
Fuel - Jetting to a certain extent... but more about does it have fuel, and is the fuel getting to the carb? Petcock closed? Float sticking?
Spark isn't too hard to check, pull the boot off, plug out, put the plug into the boot, and hold the plug firmly against the engine case while pulling the engine over. You should see a spark in there. With a 2-stroke you want to make sure the plug's gapped right and isn't fouled out.
