Re: Rebuild 115 V4 Johnson
When I started out as a machinist apprentist over 30 years ago, I ran a Sunnen honing machine. This was a machine for honing mostly small parts up to 1" in diameter. You would sit at this machine, and use a foot-pedal to apply the outwards force onto the single stone, mounted in the mandrel. You would use a hardened "bedding" cylinder, supplied by Sunnen, to "true" the stone. This "cylinder, was knurled on the outside, so you could hold it in your oil soaked hand, and had a course "cross hatch" on the inside. The opperator would slide the cylinder in and out over the mandrel, flip it around 180 degrees, slide it in and out again, to complete the truing or straightening of the stone.<br />Then, a part could be honed to exact tolerences, and a perfectly straight consistant diameter. If the stone wasn't trued every few parts, a taper would start to develop inside of holes.<br /><br />If you aren't truing your hone inside of a truing sleave, simular to this, you will have a tapered hole.<br /><br />I worked at a drag racing company, that built drag racing Kawasaki's. My primary job was boring cylinders, and fitting pistons using hand held expanding hones as you describe.<br />Trust me, if you are honing out more than .003", you will not have a straight hole.
