Got a lead down tester from Harbor Freight to try and see if I've got any issues with my 07 WR250F, this is the procedure I've followed: Although I haven't warmed up the engine, I had to manufacture an adapter for the spark plug hole as those with the unit weren't compatible, somebody said it's a 10 mm plug. Took and old plug busted the porcelain out of it and brazed the remant to a 3/8th I believe union which screws on to the hose from the tester. Got the bike to TDC on the compression stroke. Connected the hose from the plug hole to the unit, then connected the hose from the air supply. and turning the pressure regulator clockwise until the needle reached 0 on the second dial. Although the compressor regulator is set at 100 psi, the first dial will only show about 15 psi, but the second dial shows no movement at all. Video I've seen show mechanics hooking up the hose from the plug hole after doing everfything else, I seem to loose a lot of pressure right there in that process. Can anybody tell me if the way I've done it should show correct results? Thinking about just rolling over the cylinder to see if pressue start to fade as the valves open.