2007 Johnson 2 HP 4-Stroke Service Manual, Page 92Get this manual
POWERHEAD CYLINDERCRANKCASEPISTON IMPORTANT: The piston grooves must be clean, dry and free of carbon before checking clearanceFit the piston ring into the piston groove, and measure the clearance between the ring and the ring groove using the thickness gaugePiston ring to groove clearance: Standard First and Second Ring: 0.0008 to 0.0024 in(0.020 to 0.060 mm) Service limit First and Second Ring: 0.0047 in(0.120 mm) Measure the piston ring end gap with the piston ring in the lowest position of the cylinder bore
1Piston ring
Piston ring end gap:
Standard First and Second Ring: 0.006 to 1
0.014 in(0.15 to 0.35 mm)