Lil Red Barn 80mm Engine Rebuild Kit for Kohler Command Pro V-Twin Engines A complete top-end overhaul kit for Kohler's 674cc Command Pro V-twin engines. Restores compression, eliminates oil burning, and seals the engine properly for another decade of service in commercial and residential outdoor power equipment. WHAT'S INCLUDED 2 high-quality 80mm standard bore pistons (25-874-54-S) with wrist pins and circlips 2 complete piston ring sets (top and second compression rings are bidirectional for easier installation) Complete gasket set including head gaskets, valve cover gaskets, intake and exhaust gaskets, and small O-rings 2 crankshaft oil seals Tube of crankcase sealer for proper crankcase joining CRITICAL: VERIFY 80mm BORE BEFORE ORDERING Kohler produced CH620 and CH640 engines in TWO different bore sizes during production: Early production: 77mm bore, 624cc displacement (this kit does NOT fit) Later production: 80mm bore, 674cc displacement (this kit fits) Check your engine's data plate for the displacement (should read 674cc for compatibility), or measure your existing piston or cylinder bore directly. Engines with "674cc" stamped on the nameplate are the correct application for this kit. COMPATIBLE KOHLER ENGINES (80mm bore, 674cc) Horizontal shaft (CH): CH22, CH23, CH620, CH621, CH640, CH641, CH670, CH680, CH682 Vertical shaft (CV): CV22, CV23, CV620, CV640, CV670, CV680 All are 4-cycle gasoline OHV V-twin engines with cast iron cylinder liners and aluminum blocks, rated 22 HP to 24 HP. FITS SPEC-NUMBER VARIATIONS This kit fits the piston, ring, and gasket applications for the following Kohler spec numbers (partial list - if your spec number begins with CH620-, CH640-, CH670-, CH680-, CV620-, CV640-, CV670-, or CV680- and your engine is 80mm bore, this kit is compatible): CH23-76510, CH23-76524, CH23-76540, CH23-76541, CH23-76558, CH23-76570, CH23-76584, CH23-76586, CH23-76590, CH23-76596, CH23-76621, CH23-76623, CH23-76634, CH23-76636, CH23-76638, CH23-76640, CH23-76642, CH680-3001, CH680-3010, CH680-3012, CH680-3013, CH680-3015, CH680-3016, CH680-3019, CH680-3024, CH680-3025, CH680-3028, CH680-3029, CH680-3030, CH680-3032, CH680-3033, CH680-3034, CH680-3035, CH680-3036, CH680-3037, CH680-3038, CH680-3039, CH680-3040, CH680-3047, CH680-3048, CH680-3049, CH680-3051, CH680-3052, CH680-3053, CH680-3054, CH680-3055, CH680-3056, CH680-3058, CH680-3059, CH680-3060, CH680-3061, CH680-3062, CH680-3063, CH680-3072, CH680-3080, CH680-3081, CH680-3082, CH680-3083, CH680-3085, CH680-3086, CH680-3087, CH680-3088, CH680-3090, CH680-3091, CH680-3092, CH680-3093, CH680-3094, CH680-3095, CH680-3096, CH680-3100, CH680-3101, CH680-3105, CH680-3106, CH680-3107, CH680-3108, CH680-3111, CH680-3112, CH680-3113, CH680-3117, CH680-3118, CH680-3119, CH680-3120, CH680-3121, CH680-3127, CH680-3128, CV23-75520, CV23-75553, CV23-75579, CV23-75588, CV23-75598, CV23-75614, CV23-75615, CV23-75618, CV23-75619, CV23-75623, CV680-0012, CV680-0025, CV680-3001, CV680-3002, CV680-3012, CV680-3016, CV680-3019, CV680-3022, CV680-3023, CV680-3026, CV680-3027, CV680-3029, CV680-3030, CV680-3031, CV680-3032, CV680-3034, CV680-3035, CV680-3036, CV680-3037, CV680-3040, CV680-3041, CV680-3042, CV680-3044, CV680-3045, CV680-3046, CV680-3049, CV680-3051, CV680-3052, CV680-3053, CV680-3089, and additional CH620, CH640, CH670, CV620, CV640, and CV670 spec-number variations. PISTON SPECIFICATIONS Piston Part Number: 25-874-54-S Bore: 80mm (3.150") Piston Thrust Face O.D. (standard): 82.986mm (3.2671") Compression rings: bidirectional (top and second rings) Piston pin bore I.D.: 17.006-17.012mm HOW TO CONFIRM FIT Read the model number and the spec number off the blower housing decal and match them against the fitment list above. Horsepower on its own will not identify the engine, because the same horsepower was sold on more than one block and more than one bore.
- COMPLETE REBUILD KIT FOR 80mm KOHLER COMMAND PRO TWIN ENGINES - Includes 2 standard bore pistons (25-874-54-S) with wrist pins and clips, 2 piston ring sets, complete gasket set, 2 crankshaft seals, and crankcase sealer for a full top-end overhaul. Note: connecting rods, valves, and bearings are NOT included in this kit.
- VERIFY YOUR ENGINE HAS 80mm BORE BEFORE ORDERING - This kit fits ONLY 80mm bore, 674cc Kohler Command Pro Twin engines. Kohler made CH620 and CH640 engines in both 77mm (624cc) and 80mm (674cc) versions. Check your engine nameplate for displacement (674cc) or measure the bore before ordering. If your engine is 77mm bore, this kit will NOT fit.
- COMPATIBLE KOHLER ENGINE MODELS - Command Pro Twin 80mm bore, 674cc engines: CH22, CH23, CH620, CH621, CH640, CH641, CH670, CH680, CH682 (horizontal shaft) and CV22, CV23, CV620, CV640, CV670, CV680 (vertical shaft). All are 4-cycle OHV V-Twin engines with cast iron cylinder liners. Also fits many spec-number variations of these engines (CH680-3012, CH620-3090, CV680-3016, etc.).
- RESTORE COMPRESSION AND EXTEND ENGINE LIFE - Ideal for engines showing worn compression, oil consumption, blue smoke, or hard starting. These 22-24 HP Kohler Command Pro V-Twin engines power a wide range of commercial and residential outdoor power equipment including zero-turn mowers, riding lawn tractors, generators, pressure washers, and industrial machinery.
- WHAT TO MEASURE BEFORE THE KIT GOES ON - Measure each bore for taper and out of round before anything goes together. 80.00mm nominal is this kit; a worn or tapered bore wants boring and an oversize piston instead. Check ring end gap in the bore each ring will run in and side clearance in the groove, and hone the bore so the rings bed in. Clean the closure plate and pan faces to bare metal before sealer goes on.