SEALEY VALVE SPRING COMPRESSOR SET

After dyno’ing my race bike (a 1998 Honda CBR600F-W) I decided that I would skim the standard head to raise the compression. It was already at a healthy 195psi across the four cylinders, but more compression with relevant jetting/tuning should equate to more power. Sealey Tools advised me that I needed this Valve Compressor set, as it was designed as a motorcycle specific kit (product number VS1814.) The reasoning behind this was due to the length of the valves and the smaller diameters of the valve spring retainers found in motorcycle engines. On opening the storage box, there are five differently sized compressor-end adapter pieces, ranging from 16-30mm diameter, along with the compressor frame, screw thread and tommy bar. The adapter chosen for the job was the 23mm sleeve, which in operation, due to its large side access, allowed good access with a thin, telescopic magnet to remove the collets. The action of the screw thread is smooth enough to allow precise control of compression/ decompression without sending various small, fiddly bits all over the workshop. The only slight drawback I found was that the tommy bar slid out of its hole a few times. A bit of tape on each end soon sorted that. All in all, a great piece of equipment and essential to any mechanic looking to do serious head work on their machine. And yes, we did raise the compression, 225psi across the four cylinders! I’ll let you work out what that did to the power of the bike.