Connecting Rods and Pistons/Pistons and Connecting Rods 13. Measure diameter of piston pin at six places; two measurements 90˚ apart at each end and two measurements 90˚ at center. PISTON PIN SPECIFICATIONS Item New Part Wear Tolerance M35365 -UN-29AUG88 Pin O.D. B43E,B43G,B48G, P218G, P220G 17.463—17.468 mm 17.371 mm Engine (0.6875—0.6877 in.) (0.6839 in.) T260 Engine 19.050—19.055 mm 18.959 mm (0.7500—0.7502 in.) (0.7464 in.) If pin diameter is less than wear tolerance, install a new piston pin. M98,2030K,28 -19-02FEB87 CTM2 (19APR90) 30-17 16, 18, 20 & 24HP Onan Engines AllTractorManuals.com 130495 14. Measure piston pin bore in connecting rod and piston pin clearance (bore I.D.
minus pin O.D.). PISTON PIN BORE SPECIFICATIONS Engine Item New Part -UN-29JAN90 B43E, B43G, B48G, Bore I.D. 17.470—17.480 mm P218G, P220G (0.6878—0.6882 in.) B43E, B43G, B48G, Pin Clearance 0.005—0.018 mm M36398 P218G, P220G (0.0002—0.0007 in.) T260 Bore I.D. 19.06—19.07 mm (0.7504—0.7508 in.) T260 Pin Clearance 0.005—0.020 mm (0.0002—0.0008 in.) If piston pin bore diameter exceeds specifications, replace connecting rod. If pin clearance exceeds specifications, replace connecting rod, piston pin, or both. 15. Inspect connecting rod cap screws and nuts for damaged threads. Inspect connecting rods for nicks, cracks, scored bores, or bores out-of-round more than 0.05 mm (0.002 in.).
M98,2030K,29 -19-11FEB87 30 17