hi there Dave
The decomression hole is on the cylinder on the left hand side as you look from behind the motor and its upsidedown on the frame!. ive stripped the topend down, taken off the carb and exhaust, removed the little 3mm grub screw and dedoked the top piston and the head, cleaned the exhaust outlet and made sure that the hole where the grub screw came out of was spotless then reassembled only to find the problem is still there. ive tried to eliminate as much as i could without dissembling the bottom end to no avail. does anyone know what the compression gauge reading should be for the solo 210 ?and could this problem be cased by the bottomend?.