Part: Cylinder Hone for Honda CT90, Trail 90 / CB100, CL100, SL100 / CB125, CL125, SL125 / CB175, CL175, SL175 / CB200, CL200 / CB350, CL350, SL350 / CB360, CL360, CJ360 / CB450, CL450, CB500T / CB500K, CB550K, CB550F / CB750K, CB750F, CB750A motorcycles.
Why You Need This: The cylinder hone is a must have tool for a proper engine overhaul or top end rebuild on a Honda CT90 / CB100 / CB125 / CB175 / CB200 / CB350 / CB360 / CB450 / CB550. This is a tool most amateur engine builders do not know about. The ball style cylinder hone is designed to refinish the surface of the cylinder walls. This breaks any built up glaze and leaves a fresh surface for the new piston rings to seat into. If you have measured your cylinders and they are within the factory service limit published in your Honda factory service manual then you are good to hone and install a fresh set of piston rings. Cylinder hones are sold individually, pick the proper size for the engine you are working on.
We like to measure everything in an engine first (using a micrometer, telescoping snap gauges and dial bore gauge) to see what state the cylinders are in first. This lets us determine which direction to go with a rebuild. The common reaction for a rebuild is that all cylinders must be bored which is not true. Often times there is more life left in a cylinder than originally thought and a hone followed by a fresh set of piston rings is all that is needed.
Installation Tip: Lubricate the cylinder and hone with motor oil prior to use. This thing makes a mess so wear safety glasses and appropriate clothing. The honing process is done very quickly, faster than most think, drill speed should be about 800 RPM. Total time for each cylinder should be about 30 seconds initially, more time may be used depending on the results of the first session. Each pass in a single direction should be about 1/2 second with about 1/3 of the hone protruding out either end of the cylinder on each pass. The last 5 seconds of the process should have an increased stroke speed. Never stop the hone inside the cylinder; always start and remove while the hone is spinning. Freshly honed cylinders should be washed with hot soapy water and dried thoroughly as to not allow any flash rust to form. A clean white rag or paper towel should not be able to pick up any residue from the honing process; wash until the cylinder passes the clean towel test.
