Connecting Rods and Pistons/Pistons and Connecting Rods 4. Remove piston rings using a piston ring expander. IMPORTANT: Do not use a caustic cleaning solvent to remove carbon from pistons; piston may be damaged. 5. Clean carbon from piston surfaces using a wire brush. Clean piston ring grooves with a piston ring groove cleaner or the end of a piston ring filed to a sharp point. M36392 -UN-29JAN90 CTM2 (19APR90) 30-14 16, 18, 20 & 24HP Onan Engines M98,2030K,23 -19-09OCT85 AllTractorManuals.com 130495 2. Measure connecting rod bore diameter and connecting rod clearance (bore I.D. minus journal O.D.). 3. Install connecting rod cap on connecting rod.
Install and tighten nuts or cap screws evenly to specifications. -UN-29JAN90 CONNECTING ROD SPECIFICATIONS Cap Nut Torque B43E, B43G, B48G, M36391 P218G, P220G Engines 18 ± 1 N·m (159 ± 9 lb-in.) Cap Screw Torque T260 Engine 20 ± 1 N·m (177 ± 9 lb-in.) Item New Parts Wear Tolerance Bore I.D.: B43E,B43G,B48G, P218G, P220G 41.35—41.36 mm 41.39 mm Engines (1.6280—1.6285 in.) (1.6295 in.) T260 Engine 44.46—44.48 mm 44.50 mm (1.7505—1.7510 in.) (1.7520 in.) Clearance 0.051—0.084 mm 0.135 mm (0.0020—0.0033 in.) (0.0053 in.) If bore diameter exceeds wear tolerance, replace connecting rod.
If connecting rod clearance exceeds 0.135 mm (0.0053 in.), replace connecting rod or grind crankshaft connecting rod journals and install undersize connecting rods. M98,2030K,22 -19-02FEB87 30 14