A few more decisions. Refer to our engine introduction for a comparison of these engine types. If low cost is your priority, go with the bushing-equipped engine. If you're willing to pay a little more for an engine that will run smoother and last longer, look for an engine with ball bearings. An engine's piston and cylinder assembly can have either of these types of construction.
Ringed engines use an aluminum or iron piston that moves inside an iron sleeve.
The piston is surrounded by a ring that provides compression. Advantages include economy, easy starts and good power. The possible need for a longer break-in period, and greater susceptibility to damage if your carburetor is not adjusted properly. ABC engines use an aluminum piston that moves inside a chrome-plated brass sleeve. The fit of the piston and cylinder is perfected at the factory to provide excellent compression.