48275-00001 Fuel Injection Pump – Built for Mitsubishi S6R / S12R / S16R Marine Diesel Engines
When your vessel or genset relies on a Mitsubishi S-series engine – whether it’s the compact S6R, the powerful S12R, or the flagship S16R2 – the fuel injection pump is the heartbeat of the entire fuel system. The 48275-00001 injection pump assembly (also listed as 48275‑00001 or Mitsubishi 48275‑00001) is an OEM‑grade unit that delivers precise fuel metering, reliable starting, and sustained performance under the toughest marine and industrial loads.
In this guide, we break down the engineering advantages of this pump, its exact engine compatibility, common wear signals, installation best practices, and why Rsolid Engine Parts is the preferred source for this critical component.
1. Structural Features & Advantages of the 48275‑00001 Pump
The 48275‑00001 is a Bosch‑style in‑line plunger pump, widely used in Mitsubishi’s heavy‑duty medium‑speed engines. Its design focuses on durability and precision:
Hardened plunger & barrel sets – Each pumping element is matched to micron‑level tolerances, ensuring consistent fuel delivery across all cylinders and minimising uneven load.
Integrated camshaft with precision‑ground lobes – Operates with a direct mechanical or electronic governor (depending on engine configuration) for stable idle and instant throttle response.
Delivery valve with pressure‑retaining feature – Prevents secondary injection and after‑dribble, reducing carbon buildup on injector nozzles.
Rack‑and‑pinion fuel control – Delivers smooth, progressive fuel metering from idle to full load, with minimal hysteresis.
Forged cast‑iron housing – Dampens vibration and withstands the extreme cyclic pressures (up to 1,200 bar) common in high‑boost marine engines.
Corrosion‑resistant internal coatings – Protect against moisture and acidic fuel by‑products, extending overhaul intervals.
Key operational benefits:
Lower BSFC – Optimised delivery curve cuts fuel consumption by 3‑5% compared to worn pumps.
Smokeless acceleration – Properly timed injection reduces white/black smoke during startup and load changes.
Extended injector life – Stable supply pressure prevents injector nozzle erosion.
Direct drop‑in fit – No modification to mounting brackets or drive couplings.
2. Compatible Engine Models (Mitsubishi S‑Series)
The 48275‑00001 fuel injection pump is specifically designed for the following Mitsubishi marine and industrial engines:
| Engine Model | Typical Application |
|---|
| Mitsubishi S6R (including S6R‑MPTA, S6R‑YMPTA) | Tugboats, fishing vessels, auxiliary gensets, pump drives |
| Mitsubishi S6R2 | High‑output marine propulsion, emergency fire‑pumps |
| Mitsubishi S12R (S12R‑MPTA, S12R‑PTA) | Main propulsion for workboats, offshore supply, genset packages |
| Mitsubishi S16R | Large trawlers, dredgers, container ship auxiliary power |
| Mitsubishi S16R2 | High‑speed ferry, heavy‑duty industrial compressors, and mining haulage |
Cross‑reference note: The 48275‑00001 often replaces earlier numbers like 48275‑00000, 48275‑00002, and is compatible with both mechanical and electronic governor variants. Always confirm your engine serial number (e.g., 35001‑up) and pump mounting flange type.
3. Common Failures & Installation/Replacement Guidelines
Typical Failure Indicators
Erratic fuel output / hunting – Usually caused by worn plunger/barrel clearances or a sticking rack.
Hard starting or no‑start – Loss of residual pressure due to worn delivery valves or suction valve leakage.
Black smoke under load – Over‑fueling caused by a stuck control rack or incorrect timing.
Fuel in engine oil – Internal seal failure (often the camshaft oil seal) – immediate attention required.
Audible knocking – Uneven delivery between cylinders, pointing to a damaged plunger or worn cam lobe.
Professional Installation & Replacement Steps
Cleanliness first – Flush the fuel supply line and replace both primary and secondary filters. Any debris will score the new plunger instantly.
Lubricate moving parts – Use clean diesel or specified assembly oil on the plunger, rack, and tappet rollers. Never use grease – it can cause gumming.
Align timing marks – The pump drive gear and housing have punch marks. Align them precisely with the engine’s flywheel TDC mark (typically 10‑15° BTDC, per engine manual).
Torque mounting nuts evenly – Flange bolts: 55 ± 5 N·m (staged cross‑tightening). Over‑torquing distorts the housing.
Install new delivery valve holders & copper washers – Always use fresh washers to guarantee leak‑free high‑pressure seals.
Bleed the system – Open the air vent screw on the pump and prime until fuel flows without bubbles. Then bleed each individual injector line.
Governor adjustment – If equipped with an electronic actuator, recalibrate the zero‑position and max‑fuel stops using the manufacturer’s software (e.g., Mitsubishi M‑PSI).
Post‑installation check – Run the engine at idle and gradually load it. Perform a cylinder‑cut test to ensure uniform fuel delivery (± 3% variance max).
4. Why Rsolid Engine Parts Is Your Trusted Supplier
Rsolid Engine Parts has been a dedicated aftermarket supplier for Japanese and American diesel fuel systems since 2008. Here’s why fleet operators and workshops choose us for the 48275‑00001 pump:
True OEM‑grade manufacturing – Sourced from ISO 9001:2015 & IATF 16949 certified factories, with identical metallurgy and dimensional specs to genuine Mitsubishi pumps.
100% bench‑tested – Each pump is run on a Bosch‑type calibration stand; we supply the test report with delivery curves for every cylinder.
Ready stock & fast dispatch – Warehouses in Asia, Europe, and the US ensure 3‑7 day delivery worldwide.
Competitive tiered pricing – Discounts for workshops, fleets, and wholesale buyers. Ask about our core exchange program.
Expert technical help – Our team provides free timing data, wiring diagrams, and governor setup assistance.
Solid warranty – 18 months / 3,000 hours against defects in materials and workmanship – no‑hassle replacement.
Contact Rsolid Engine Parts Now
📧 Email: amy@rinjector.com
📱 WhatsApp: +86 15975376778
Whether you need a single pump for an S6R or a full set of 12‑cylinder pumps for an S16R2, Amy will respond with a detailed quote within 2 hours. We also supply complete gasket kits, delivery valves, and plunger sets for your overhaul.
