My Engine won't start.

These engines require only a few basic ingredients in order to start. If one is missing, they will not 'go'. These things are... Fuel, air, compression and spark.

It's important to identify that you have all of these things. Lets take them one at a time...

Fuel...when priming does the bulb fill? After several pulls of the pullstart, remove the plug. Is it wet? If the answer to both of those is yes, the problem is not that the fuel is not getting through. If it seems like not enough fuel is getting through, try returning the needles to [link=http://www.rcuniverse.com/forum/fb.asp?m=7217622]factory settings[/link].

Air...remove and check the air filter for excessive dirt/blockages, look into the carb, check it's clear. Everything ok? Moving on...

Spark...remove the spark plug. With the spark plug out, reattach the lead and ground the thread of the plug on a metal part of the engine. Pull the pull starter. You should see a clean strong blue spark. If not, then replace the plug, or check the coil.

Compression...is a little bit tougher to test for, but if you get no resistance to your pulls on the pull starter, then chances are there is little or no compression in the engine. If this is the case, check the seals, gaskets, piston, ring, etc to see where the pressure is escaping.