Yanmar 729685-51330 / 729247-51390 High-Pressure Fuel Pump: Common-Rail Fitment, Test Data and Diagnostic Guide for 4JH/4TNV
1. Product: 729685-51330 & 729247-51390
2. Compatible Equipment: Diesel Fuel Injection Systems
3. Manufacturer: Aftermarket OEM Replacement
4. Condition: Brand New, Fully Tested
5. Origin: ABOSEDE Diesel
6. Shipping period: 3-5 business days
7. Payment terms: T/T, Western Union, PayPal
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Product Introduction
When a Yanmar common-rail engine loses rail pressure, the high-pressure pump is often blamed first. In reality, the pump is one node in a chain that includes lift supply, filtration, suction control, pressure limiting, injector leak-off, return lines and ECU calibration. The Yanmar 729685-51330 and its service alternative 729247-51390 are radial-plunger high-pressure pumps used across 4JH and 4TNV engine families. This guide is written for technicians, parts buyers and fleet maintainers who need fitment logic, bench data and diagnostic direction-not a generic product description.
📌 Fitment & Replacement Logic
The 729685-51330 and 729247-51390 are not interchangeable by appearance alone. Before ordering, confirm the pump number on the nameplate, engine model, serial range, ECU calibration and connector/control-valve type. The 729247-51390 is commonly treated as a service replacement for 729685-51330 in certain 4JH and 4TNV applications, but the final match must be verified against the engine's parts catalog and injection system variant.
| Check Item | Why It Matters |
|---|---|
| Pump number | 729685-51330 vs 729247-51390 may differ in control interface or calibration |
| Engine family | Yanmar 4JH, 4TNV marine, industrial and generator applications |
| ECU / rail strategy | Pressure target and metering response must match the ECM |
| Return and inlet fittings |
Prevents installation delays and fuel starvation
|
🧭 Application Coverage & Search Intent
Typical users search for this pump by Yanmar 4JH fuel pump, 4TNV high-pressure pump, 729685-51330 replacement, 729247-51390 common rail pump, and rail-pressure fault symptoms. Common equipment includes marine propulsion engines, marine generator sets, skid-steer loaders, mini excavators, refrigeration units and auxiliary industrial power packs. The correct approach is to match the pump to the engine serial and injection system, not only to the machine model.