1988 "CC" Colt / Junior thru 8 Models Service Manual, P/N 507659, Page 39Get this manual
Engine Specifications 4BR Operation Full Throttle Operating Range Power Power Rated Idle RPM in Gear Test Wheel Minimum Test Wheel RPM Weight (Empty Integral Tank or Separate Tank): Standard Length Long Shaft Powerhead Displacement Bore Stroke Standard Bore 5.28 cu in(87 cm1.565 in(39,7 mm) 1.374 in (34,9 mm) 4500 to 5500 RPM 4HP(3kw) 5000 RPM 625 25 RPM OMC PIN 317738 4400 RPM
33 Ibs(15 kg) 35 Ibs(15,9 kg)
1.5643-1.5650 in (39,74-39,75 mm)
Crankshaft Dimensions: Top Journal Center Journal Bottom Journal Rod Crankpin Piston Diameter, Standard Piston Ring End Gap, Both Piston Ring Groove Side Clearance, Both .7506-0.7510 in (19,06 -19,08 mm) .6685-0.6690 in(16,98-16,99 mm) 0.7498-0.7502 in (19,05-19,06 mm) 0.6695-0.6700 in (17,00-17,02 mm) 1.5610-1.5635 in (39,65-39,71 mm) .005 -0 .015 in(0,13-0,38 mm) 0.004 (0, 10 mm) maximum