pengenalan
This manual provides essential information regarding the FridayParts 4JB1 Engine Overhaul Rebuild Kit. This kit is designed for the complete overhaul of Isuzu 4JB1 2.8L engines, commonly found in Bobcat Skid Steer Loaders models 843, 853, and 1213. It includes all necessary components for a comprehensive engine rebuild, specifically featuring pistons with a square base and 31MM diameter piston pins.
For optimal performance and safety, it is highly recommended that installation be performed by a qualified and experienced mechanic. Refer to the specific service manual for your engine and equipment model for detailed disassembly and assembly procedures.
Product Compatibility and OEM References
This rebuild kit is compatible with Isuzu 4JB1 2.8L engines and the following Bobcat Skid Steer Loader models:
- Bobcat 843
- Bobcat 853
- Bobcat 1213
- Bobcat 960
- Bobcat 2060
- Bobcat 2070
Nombor Bahagian OEM: 5-87311-082-0, 8-94247-861-2, 8-94332-326-0, 5873110820, 8942478612, 8943323260.
Kandungan Kit
The FridayParts 4JB1 Engine Overhaul Rebuild Kit includes the following components:
- Full Overhaul Gasket Kit: 1 Set (Includes various gaskets and seals required for a complete engine rebuild.)
- Omboh: 1 Set (Includes pistons with square base and 31MM diameter piston pins.)
- Piston Ring: 1 Set (Complete set of piston rings for all cylinders.)
- Piston Pin: 1 Set (Piston pins for connecting pistons to connecting rods.)
- Cylinder Liner: 1 Set (Cylinder sleeves for all cylinders.)
- Piston Snap: 1 Set (Retaining clips for piston pins.)
- Piston Pin Bush: 1 Set (Bushings for piston pins.)
- Thrust Washer STD: 1 Set (Standard size thrust washers.)
- Main Bearing STD: 1 Set (Standard size main bearings.)
- Con Rod Bearing STD: 1 Set (Standard size connecting rod bearings.)
- Valve Guide: 1 Set (Valve guides for cylinder head.)
- Intake & Exhaust Valve: 1 Set (Complete set of intake and exhaust valves.)
- Intake & Exhaust Valve Seat: 1 Set (Valve seats for cylinder head.)
Nota: Standard (STD) size bearings are included by default. If oversized bearings (+0.25mm or +0.5mm) are required, please ensure to specify this when ordering or contact customer support.

Rajah 1: Berakhirview of the FridayParts 4JB1 Engine Overhaul Rebuild Kit components. This image displays the full set of parts including pistons, rings, gaskets, bearings, valves, and cylinder liners, arranged for clear viewing.

Rajah 2: Another perspective of the FridayParts 4JB1 Engine Overhaul Rebuild Kit, showcasing the various components from a different angle to highlight all included parts.
Garis Panduan Persediaan dan Pemasangan
The installation of an engine overhaul kit requires specialized tools, knowledge, and adherence to precise torque specifications and clearances. This section provides general guidelines; always consult the official service manual for your specific engine and equipment model.
- Penyediaan:
- Ensure the engine block and cylinder head are thoroughly cleaned and inspected for cracks, warpage, or damage.
- Measure cylinder bores, crankshaft journals, and connecting rod bores to confirm they are within manufacturer specifications.
- Verify all new components match the specifications of the original parts, especially piston type (square base) and piston pin diameter (31MM).
- Pemasangan Komponen:
- Cylinder Liners: Install new cylinder liners, ensuring proper seating and protrusion if applicable.
- Pistons and Rings: Assemble piston rings onto the new pistons. Install piston pins and snap rings, ensuring correct orientation. Lubricate all components with clean engine oil before installation.
- Galas: Install main and connecting rod bearings. Ensure correct clearance using plastigauge or similar methods.
- Crankshaft and Connecting Rods: Install the crankshaft and connecting rod assemblies, torquing all fasteners to manufacturer specifications.
- Valves and Valve Guides: Install new valve guides, valves, and valve seats into the cylinder head. Ensure proper valve seating and spring tension.
- Gaskets and Seals: Use the full overhaul gasket kit to seal all engine components, paying close attention to head gasket orientation and torque sequence.
- Perhimpunan Akhir:
- Reassemble all external engine components, ensuring all connections are secure and properly torqued.
- Fill the engine with the recommended type and quantity of engine oil and coolant.
Amaran: Incorrect installation can lead to severe engine damage and void any warranties. Professional installation is strongly advised.

Rajah 3: Terperinci view of a piston included in the kit, highlighting its square base design and the 31MM diameter piston pin bore. This specific design ensures compatibility with the intended engine models.

Rajah 4: Atas ke bawah view of a piston, clearly showing the square combustion chamber base. This visual confirms the piston type for correct application.

Rajah 5: Pro sampinganfile of a piston, illustrating the ring grooves and the overall construction. This view helps in understanding the piston's dimensions and ring placement.
Operating Considerations After Rebuild
After a complete engine overhaul, a proper break-in procedure is crucial for the longevity and performance of the engine. Consult your engine's service manual for specific break-in recommendations.
- Permulaan permulaan: Ensure adequate oil pressure is established immediately upon starting. Monitor for any unusual noises or leaks.
- Tempoh Pecah Masuk: Operate the engine under varying loads, avoiding prolonged idling or full-throttle operation for the first few hours (typically 20-50 hours).
- Perubahan Minyak: Perform an initial oil and filter change after the first 50-100 hours of operation to remove any break-in contaminants.
- Pemantauan: Regularly check fluid levels (oil, coolant) and monitor engine temperature and pressure gauges during the initial operating period.
Penyelenggaraan
Regular maintenance is essential to ensure the continued reliability and performance of your rebuilt engine.
- Oil and Filter: Adhere to the manufacturer's recommended oil change intervals and use specified oil types and filters.
- Sistem Penyejuk: Maintain proper coolant levels and ensure the cooling system is free of leaks and blockages. Flush and replace coolant as per manufacturer guidelines.
- Penapis Udara: Regularly inspect and replace the air filter to prevent contaminants from entering the engine.
- Sistem Bahan Api: Ensure the fuel system is clean and free of contaminants. Replace fuel filters as recommended.
- Injap pelepasan: Check and adjust valve clearances according to the engine manufacturer's specifications at recommended intervals.
Menyelesaikan Masalah Isu Biasa
This section addresses general troubleshooting steps for issues that may arise after an engine rebuild. Always consult a qualified mechanic for complex problems.
| Isu | Kemungkinan Punca | Tindakan |
|---|---|---|
| Tekanan Minyak Rendah | Incorrect bearing clearances, faulty oil pump, clogged oil passages, low oil level. | Check oil level. Verify oil pump operation. Re-check bearing clearances if recently rebuilt. |
| Enjin Terlalu Panas | Insufficient coolant, air in cooling system, faulty thermostat, clogged radiator, incorrect ignition timing. | Check coolant level and system for leaks. Bleed air from cooling system. Inspect thermostat. |
| Asap Berlebihan | Blue Smoke: Worn piston rings/valve guides. Black Smoke: Rich fuel mixture. White Smoke: Coolant in combustion chamber (head gasket). | Diagnose smoke color. Check compression, inspect head gasket, verify fuel system. |
| Bunyi Enjin Luar Biasa | Loose components, incorrect valve lash, bearing knock, piston slap. | Identify source of noise. Re-check torque specifications. Adjust valve clearances. |
Spesifikasi
Key specifications for the FridayParts 4JB1 Engine Overhaul Rebuild Kit and related engine components:
- Model Enjin: Isuzu 4JB1 (2.8L)
- Jenis omboh: Square Piston Base
- Piston Pin Diameter: 31MM
- Bearing Sizes: Standard (STD) - Oversizes (+0.25mm, +0.5mm) available upon request.
- Kit Weight: Kira-kira 26.4 paun (11.97 kg)
- Dimensi Pakej: Kira-kira 23.5 x 14.5 x 7 inci (59.7 x 36.8 x 17.8 cm)
- Nombor Bahagian Pengilang: 4JB1 Overhaul Rebuild Kit
- ASIN: B07MTCP6WH
Waranti dan Sokongan
For information regarding warranty coverage, returns, or technical support for your FridayParts 4JB1 Engine Overhaul Rebuild Kit, please contact the seller directly through your purchase platform. Ensure you have your order details and product information readily available.
Penjual: FridayParts
For additional product information or to explore other offerings, you may visit the FP FRIDAYPARTS Store.

