1)Step 1: STARTER BOX WIRED BACKWARDS Don’t laugh; we’ve seen it many times! Your engine might start, but the chances are slim. Before you check and replace the glow plug, fuel, fuel lines, etc., make sure the starter box spins the flywheel in the correct direction! 2)Avoid this mistake by paying attention when you connect your battery and motor wires. Looking directly at the front of the engine (looking straight at the crankshaft), you should see the starter wheel spinning clockwise to spin the flywheel counterclockwise Check your radio equipment before a day of running your nitro car. Forgetting to turn on, turn off, charge, or replace your transmitter or receiver batteries is high on the list of causes that start an expensive nitro disaster. Always charge radios and receiver packs overnight before you plan to race. If your system uses alkaline “dry” cells, replace them with fresh ones before a full day of running. To eliminate the chances of accidentally turning your radio and/or receiver on when transporting your equipment, disconnect the receiver battery from the switch harness, and completely remove the transmitter batteries before you pack your gear. Insert the batteries at the track or wherever you run. Before you start your engine, always run through a radio-system check to ensure that all controls function properly. If your servos move slowly or not at all, something needs attention. 3)An engine’s only defense against contamination is its air filter. Run an engine for extended periods in dusty places without an air filter, and you can kiss it goodbye! Zip-tie the filter to your engine’s carburetor; you may think it will stay in place on its own because it fits snugly, but one good bump can send an unsecured filter flying. Use a small zip-tie to secure the filter body to the carb neck. Remove any oil or grease that’s on the carb neck and the filter elbow with denatured alcohol or nitro cleaner. Next, tighten the zip-tie until it is snug but not too tight (excessive pressure can cause the filter elbow to slip off the carb neck). 4)This is yet another mistake from the “duh!” handbook of what not to do when you prepare your engine for operation. Air-filter elements arrive oiled or dry; if your filter is already oiled, adding more oil will starve the engine of air. Oiling a dry filter too much also equals no air for the engine. Filter oil is clearly one of those things where more is not better. Avoid choking your engine by using only as much filter oil as is necessary to completely oil it. After you've oiled it, remove any excess by squishing it in a paper towel. 5)Don’t push the filter into the carb to stop the engine. This is a big-time no-no; you can easily push contaminants through the filter element and into the carb or push the element into the carb neck. Stop your engine simply by picking up your vehicle and touching the tip of your shoe to the flywheel. This works particularly well during a runaway when the engine is revving out of control and you don’t want to touch a hot exhaust pipe or carburetor. You could also pinch the fuel line to shut the engine down. To eliminate the possibility that you’ll inadvertently contaminate your engine, stop it in the proper way. 6)At some point, nearly every experienced nitro junky has attempted to start an engine without fuel.It’s an easy-and embarrassing!-mistake. Before you yank the pull-starter or bump the flywheel against the starter box, just check your fuel. This check is especially important after you’ve taken a break in the middle of a race, as it’s easy to forget whether you filled the tank or not! 7)Not sure why your engine won’t start? Maybe the glow igniter is causing the problem. Rechargeable and alkaline-powered igniters may be out of juice, and this is easily overlooked, especially if your igniter doesn’t have a meter. Install a fresh alkaline battery, or recharge your igniter overnight before you hit the track. Not sure whether your plug or the igniter itself has gone bad? Even if your glow igniter has a meter, it tells you only that something isn’t working; it doesn’t tell you what. Perhaps your battery is dead, or the glow plug is damaged. Try a friend’s igniter with your plug, and you’ll soon know whether your igniter or your plug is causing the problem. Or try a new glow plug with your igniter. If it doesn’t glow bright orange/white, your igniter is out of juice. 8)It’s easy to be careless and to attach the wrong line to the exhaust pipe, the fuel tank or the engine. Obviously, an engine will not run if the pressure line feeds the carb air instead of fuel. Carefully check your fuel and exhaust pressure lines to ensure they’re attached correctly. To avoid making this error, mark the pressure line (or the fuel line-your choice) with a permanent-ink pen. A simple black band will alert you to which line is which. 9)When you rebuild an engine, it’s important to ensure that the piston is properly oriented. Engines with piston-skirt cutouts allow the piston to drop to its lowest point without striking the crankshaft’s counterweight or the backplate. Many engine backplates have a relief or a groove to allow clearance for the piston, so it’s equally important to orient the backplate properly when you install it, or you won’t be able to crank the engine over without breaking the piston skirt. The pistons in engines without piston-skirt cutouts may have holes that align with ports on the sleeve. Consult your engine’s manual if you aren’t sure how to align the piston properly. Always pay careful attention to the piston’s orientation before you remove it from the engine the first time! 10)It’s easy to set the mesh incorrectly; the gears either bind because the mesh is too tight, or they hardly touch because they barely mesh. An overly tight gear mesh will bind the drive train, overheat your engine and its clutch components, stress the clutch-bell bearings and slow the car considerably. An excessively loose mesh will quickly strip the gears. To set your gear mesh properly, slip a strip of regular notebook paper between the clutch bell and the spur gear, and then press the engine toward the spur gear while you tighten the engine-mounting screws. 11)We always stress this for metal-to metal contacts, but some people still forget. I’ll say it again: use thread-locking liquid! Nitro cars’ notoriously strong vibrations will rattle fasteners loose in a hurry. Forget to thread-lock your vehicle’s screws, and you may find yourself picking up parts or chasing down runaway wheels after they’ve vibrated loose. Take your time to build every vehicle properly by using thread-locking liquid on all metal-to-metal fasteners. Buy the blue “medium” formula; it isn’t as permanent as the red “high-strength” formula, but it's stronger than most green “light-hold” formulas. Put a dab of liquid thread-lock on the screws before you thread them in. Don’t use too much; it doesn’t do a better job than a small drop. If you’ve been into RC for more than a day, you’ll know that mistakes are easy to make but just as easy to avoid. Regularly run through this list, and you’ll enjoy run time instead of frustration time spent solving problems caused by your mistakes. hope this helped u out!