My Reassembly Instructions: Lube all parts with engine oil. Install left + right valves and keep the top of the gears flush with the top of the cylinder. Install the main exhaust valve (5) but keep it out 1/2" while installing the long geared shaft. Turn the shaft so that the teeth face correctly for proper mating with the gear teeth of the valves, insert the shaft, and then install the retaining screw. Pull to the right the long shaft and push in the exhaust valve so that the flat spot on the end of its shaft is facing up (+ is closest to the top of the cylinder) and the valve inside is open (allowing more exhaust flow with high revs). Then push the exhaust valve deeper in and install its outer cylinder. Position the left + right valves according to the installation diagram so that the indentations are positioned correctly. Then push the valves deeper in and install the idle gear with its indentation according to the diagram. Then install the three guide/retainers and two o-rings. Put the circlip on the main exhaust valve and install the cover with two bolts. Manually move the long shaft in and out to check that it moves freely. If not, then disassemble and clean again (especially the gear teeth). If you get tired of replacing these valves once or twice a year then just do as I did and glue the broken ones in the open position with epoxy glue. You'll lose just a bit of low end power but keep the top end power (which is where all the fun is). Due to a bad port design, they don't really allow a lot of flow anyway. Look into the exhaust port and you'll see that the output window for them is half the size of the original double port in the cylinder. To make up for the power loss just buy high tension carbon fiber reeds and an NGK BR8EVX plug, and do this piston mod: This mod is to help intake flow from bottom dead center to where the skirt raises enough to allow air/gas flow under it from the reeds. This is done by drilling a few holes in the intake skirt. The stock piston has one hole in the middle with its center 38mm down from the piston top. I enlarged it to 3/8" (9mm) diameter. I also made two holes 3/4" (19mm) to the left and right of the intake centerline and 34mm down from the piston top, that have a 1/4" (7mm) diameter (which I may enlarge to 3/8" (9mm) diameter). And I made one little hole in the centerline (22mm down) with 3/16" (4.5mm) diameter to aid circulation under the piston crown which combats heat buildup there. The 3 main holes help with mid range power.