OuttaLuck
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Help! My Zenoah or Chung Yang RC-style engine won't start! What's wrong?
This engine is tuned for high performance and needs to be well taken care of. If your engine won't start, check the following things:
1) Are you using high octane gasoline? 91 octane or higher is needed. Using octane booster is not recommended.
2) Are you using high-quality 2-stroke oil mixed at 25:1? This is 5 ounces of oil per gallon. DO NOT USE any oil labeled as 'TCW-3', 'MARINE' or 'OUTBOARD' oil. These are designed for low-revving, water-cooled oil-injected motors (such as personal watercraft), and your engine will likely not run well if you use them.
3) Are you using the choke properly? On the side of the carburetor there is often a choke lever. Horizontal is open, vertical is closed. Lever should be closed when first starting. As soon as the engine sputters at all, move the choke to open and leave it there.
4) Is your spark plug clean and working? Remove the plug from the engine and inspect the tip. Is it clogged with gunk or debris? Clean if necessary. After the plug is removed, check if the plug is working by: attaching the wire to the top of the plug, and place the tip of the plug very close to the metal of the cylinder. Pull the pull start a few times. A spark should jump from the plug to the cylinder. If no spark or weak spark, replace the plug, ensure the ignition coil and flywheel are properly gapped, then check again. If still no spark - you likely have a problem with the ignition coil, and will need professional service.
5) Is your carburetor properly tuned? Rotate the 'H' and 'L' screws on the side of the carb fully clockwise ('closed'). Then, turn the L screw counterclockwise ('open') 1 and 1/4 turns. Turn the H screw open 1 and 3/8 turns. You may need to adjust these screws slightly in either direction to find correct tuning for your carb.
6) Is your engine flooded? If you have pushed the primer bulb a lot of times, or pulled the pull start a lot of times, the engine may be flooded. Remove the spark plug, and allow all the fuel in the cylinder to evaporate. You can speed up this process by blowing on it with a hair dryer, and/or by turning the engine upside down with the spark plug out and pulling the starter a few times to purge accumulated fuel from the crankcase.
7) Are you getting good compression? If you have used your engine for an extended period of time, the piston ring may need replacement. See instructions below.
8) Do you have a gasket leak? Check your carb gasket, intake gasket, cylinder gasket, and crankcase gasket. Can you hear air whooshing out of the cylinder gasket or crankcase gasket when you pull the starter? Is air leaking in the manifold gasket behind the carb? A gasket leak results in a loss of compression and/or improperly mixed fuel and air. An easy way to check for intake leaks is to spray the intake manifold and area surrounding it with WD-40. If the idle changes after you spray the WD-40, there is an intake air leak. Common areas for leaks are between the manifold and the cylinder, and between the carb and the intake manifold. Inspect the manifold, carb gasket, and intake gasket for cracks or other signs of damage, and replace if necessary.
If your engine still won't start, you will likely need professional service on your engine.
This engine is tuned for high performance and needs to be well taken care of. If your engine won't start, check the following things:
1) Are you using high octane gasoline? 91 octane or higher is needed. Using octane booster is not recommended.
2) Are you using high-quality 2-stroke oil mixed at 25:1? This is 5 ounces of oil per gallon. DO NOT USE any oil labeled as 'TCW-3', 'MARINE' or 'OUTBOARD' oil. These are designed for low-revving, water-cooled oil-injected motors (such as personal watercraft), and your engine will likely not run well if you use them.
3) Are you using the choke properly? On the side of the carburetor there is often a choke lever. Horizontal is open, vertical is closed. Lever should be closed when first starting. As soon as the engine sputters at all, move the choke to open and leave it there.
4) Is your spark plug clean and working? Remove the plug from the engine and inspect the tip. Is it clogged with gunk or debris? Clean if necessary. After the plug is removed, check if the plug is working by: attaching the wire to the top of the plug, and place the tip of the plug very close to the metal of the cylinder. Pull the pull start a few times. A spark should jump from the plug to the cylinder. If no spark or weak spark, replace the plug, ensure the ignition coil and flywheel are properly gapped, then check again. If still no spark - you likely have a problem with the ignition coil, and will need professional service.
5) Is your carburetor properly tuned? Rotate the 'H' and 'L' screws on the side of the carb fully clockwise ('closed'). Then, turn the L screw counterclockwise ('open') 1 and 1/4 turns. Turn the H screw open 1 and 3/8 turns. You may need to adjust these screws slightly in either direction to find correct tuning for your carb.
6) Is your engine flooded? If you have pushed the primer bulb a lot of times, or pulled the pull start a lot of times, the engine may be flooded. Remove the spark plug, and allow all the fuel in the cylinder to evaporate. You can speed up this process by blowing on it with a hair dryer, and/or by turning the engine upside down with the spark plug out and pulling the starter a few times to purge accumulated fuel from the crankcase.
7) Are you getting good compression? If you have used your engine for an extended period of time, the piston ring may need replacement. See instructions below.
8) Do you have a gasket leak? Check your carb gasket, intake gasket, cylinder gasket, and crankcase gasket. Can you hear air whooshing out of the cylinder gasket or crankcase gasket when you pull the starter? Is air leaking in the manifold gasket behind the carb? A gasket leak results in a loss of compression and/or improperly mixed fuel and air. An easy way to check for intake leaks is to spray the intake manifold and area surrounding it with WD-40. If the idle changes after you spray the WD-40, there is an intake air leak. Common areas for leaks are between the manifold and the cylinder, and between the carb and the intake manifold. Inspect the manifold, carb gasket, and intake gasket for cracks or other signs of damage, and replace if necessary.
If your engine still won't start, you will likely need professional service on your engine.