For improving the performance of your stock 150cc scooter, you will need to make some changes to how the components operate. Fortunately, many of these changes are simple to make and can be done with basic automotive tools. A 150cc scooter typically comes with a decent engine that can hit about 50 mph, but many owners want to give their rides a bit more pep if possible. Follow the steps below to make minor changes to fuel flow and electrical that can produce some immediate power changes.
Locate your scooter carburetor connected to the intake valve entering the scooter engine cylinder. Disconnect the rubber hose connecting the air intake of the carburetor to the scooter frame (opposite of the carburetor side connecting to the engine). Purchase a foam filter from a motorcycle shop that fits the size of your carburetor opening. Install it on the opening and secure the filter with a screwdriver and the clamp that comes with the filter.
Find the top of spark plug in the scooter cylinder in the center of the cylinder cap at the front of the scooter engine. Disconnect the ignition cap on the spark plug. Loosen the existing spark plug with a socket wrench and socket. Remove the old plug and replace it with a high performance type spark plug for improved ignition. Retighten the new plug using the socket wrench. Re-insert the ignition cap.
Purchase a no-limit ignition coil known as a CDI for your scooter. Use a screwdriver to disconnect the old stock CDI on the scooter from its bracket on the engine. Disconnect the electrical wiring to the engine. Screw in the new CDI and connect the wiring.
Use a screwdriver to remove the oil hose from the engine. Drain the old engine oil and replace it with new synthetic engine oil. Reconnect the hose and tighten its clamp to the engine with a screwdriver. Use a crescent wrench and drain the transmission oil as well from the bottom of the engine. Plug the bottom bolt again and insert new transmission oil in the fill hole.
Locate your fuel tank hose line connection running from the gas tank to the engine. Use a screwdriver to disconnect the old plastic clear hose, prone to collapsing, and clamps from the tank and engine. Replace this with stronger non-collapsible braided fuel line with a ¼ inch internal hose diameter. Install the new fuel line and secure the clamps with a screwdriver.
Use a socket wrench to loosen the current exhaust pipe connection to the cylinder and engine frame. Pull the old exhaust off. Purchase a performance exhaust for your model scooter. Bump the cylinder end of the exhaust onto the cylinder stub first, using a rubber mallet. Secure the new exhaust bracket to the engine frame second with the socket wrench. Tighten until it's firmly secured, or attach the cylinder springs if applicable.
