The Ryobi CS26 weed eater operates with an internal combustion engine that ignites fuel inside a small cylinder. This fuel powers the piston and crankshaft. Fuel is delivered to the cylinder through a special carburetor, which processes the fuel's mix. Specifications set by Ryobi are designed to help owners maintain the highest level of engine performance on the tool.
The piston on the CS26 sits on top of the crankcase in the cylinder. When fuel ignites in the trimmer's chamber, spark helps push the piston up and down. This means that the CS26 is a two-stroke engine because as engine functions require only two movements of the piston. The size of the piston’s displacement, often referred to as cc’s, is 26 cubic centimeters. This engine weighs 8.7 pounds without fuel and about 10 pounds with fuel.
When the piston goes up, it creates suction and pressure. This pressure allows the carburetor to pull fuel up from the tank and into the carburetor. The carburetor uses a plastic diaphragm inside the fuel pump, which pulses with crankcase pressure, to create the suction needed to pull fuel up. The trimmer's carburetor, known as an all-position or butterfly valve carburetor, works through three sections. The metering section portions off the necessary fuel for correct engine speed. The mixing section mixes the fuel with air at the fuel pump. The setting for the carburetor screws is set at the factory and only a professional should adjust these settings.
The CS26 requires a different fuel than most lawn mowers and other outdoor tools. Two-cycle engines don’t have an oil pump to lubricate the crankcase, so they must get lubrication from the fuel source. Two-stroke engine oil is mixed directly into gasoline before fuel is poured into the tank. The CS26 requires regular unleaded fuel with an octane rating of 87 or more. It can’t operate with blended fuels or fuels with additives, such as ethanol. The mixing specifications are 1 gallon of gasoline to 2.6 ounces of engine oil.
The ignition system on the CS26 is capacitor discharge, which means a charges fires off an ignition module. This module develops, holds and delivers the charge with an electric coil and high-voltage wires. These wires connect to the end of the spark plug and cause it to spark. The CS26 requires a specific spark plug for it to properly ignite fuel. Use an RCJ 6Y spark plug with an electrode gap of .2 millimeters to .3 millimeters.