Matched Engine Auxiliary Supply — Fuel shutoff solenoid plus adjacent gaskets and fasteners verified against your specific Bobcat engine serial before dispatch.
Technical Specifications
| Parameter |
Value |
| Part Number |
6681513 |
| Product Type |
Stop Solenoid |
| Cross-Reference |
6681513 (reference only) |
| Voltage |
12V |
| Machine Fitment |
Bobcat 751, 753, 763, 773, 5600, 7753, S150, S160, S175, S185, T190, 325, 328, 331, 334, 337, 341 |
| Condition |
New Aftermarket |
| Warranty |
3-12 months against manufacturing defects |
| Manufacturing Standard |
ISO-certified |
Application Suitability
| Engine System |
Related Components |
| Fuel Shutoff Control |
Fuel line gaskets, mounting hardware, electrical connector terminals |
| Engine Auxiliary |
Fuel filters, injection line seals, return line check valves |
| Electrical Supply Circuit |
Relay assembly, wiring harness sections, fuse links |
Diagnosing the Root Cause Before a Stop Solenoid engine rebuild
A burned coil often points to a wiring fault, not a defective solenoid.
In our Guangzhou workshop, we regularly see Bobcat skid steers come back within weeks after a stop solenoid replacement because the underlying electrical or fuel delivery fault was never traced. The coil burns out again for the same reason it failed the first time. Technicians focused on the visible casualty instead of the invisible cause. [NEED_CITE: electrical fault diagnosis procedures for mobile diesel engine auxiliary systems] A proper stop solenoid engine rebuild addresses relay contacts, harness insulation breakdown, and connector corrosion alongside the solenoid itself.

The Fuel Shutoff Circuit Within the Broader Engine System
This stop solenoid sits at the terminal point of the fuel delivery path, responsible for cutting supply when the ignition cycles off. On Bobcat machines from the 753 through the S185, the solenoid receives its signal through a relay circuit that is itself subject to contact wear and voltage drop over years of vibration exposure. When planning a stop solenoid engine rebuild, inspecting the upstream relay and the connector pins for heat discoloration tells you whether the new solenoid will survive or repeat the failure cycle.
Engine Serial Variants and Electrical Compatibility
Bobcat fitted several engine families across the 325, 331, 337, and T190 model ranges over successive production years, and the electrical architecture shifted between them. The physical mounting pattern may remain identical while the coil resistance specification and connector pinout change. Supplying a stop solenoid engine rebuild without confirming the engine serial number risks installing a 12V coil into a circuit that delivers intermittent overvoltage from a failing regulator. We cross-reference your engine serial against the specific auxiliary configuration to prevent this mismatch. [NEED_CITE: engine serial variant identification for compact equipment fuel systems]
Reading the Specifications That Determine Field Performance
The 12V rating defines the nominal operating voltage, but the coil must tolerate the charging system's output, which regularly reaches higher levels during engine operation. The ISO-certified manufacturing standard ensures dimensional consistency in the plunger bore and seat interface, which directly governs how cleanly the valve seals against fuel pressure when de-energized. New aftermarket condition means the internal spring tension and plunger travel fall within original design parameters rather than accumulated wear tolerances. The 3-12 month warranty covers both the electromagnetic coil function and the mechanical sealing surface, recognizing that failure can originate in either domain.

The Cost of Skipping System-Level Diagnosis
Replacing the solenoid without testing relay contact resistance and harness continuity often produces a second failure before the first service invoice is paid. The machine returns to the workshop, the technician assumes the replacement part was defective, and a third solenoid goes in. By this point, the fuel line gaskets have been disturbed multiple times, introducing leak paths that create their own symptoms. The cumulative cost in labor hours and repeated downtime far exceeds the time required to trace the circuit properly during the first repair. [NEED_CITE: repeat failure patterns in diesel engine auxiliary electrical components]
Why Source This Solenoid Through Our Engine System Desk
Our own production lines and qualified sourced partners operate under the same quality inspection and warranty terms, so your stop solenoid arrives with documented coil resistance and operational test results regardless of which facility built it. Eight product categories under one account means the fuel line gaskets, electrical connector repair kits, and mounting hardware ship in the same consignment as the solenoid itself. Guangzhou warehouse stock on fast-failure auxiliary items enables rapid dispatch when a machine is waiting. Part identification from your engine serial number, a photograph of the nameplate, or the worn connector face ensures correct variant selection. Cross-reference verification covers superseded numbers across Bobcat production generations. Technical team confirmation of compatibility and grade before you commit to bulk eliminates the trial-fitment gamble.
Documentation & Verification
- Commercial invoice listing solenoid coil voltage and machine compatibility reference
- Cross-reference sheet mapping superseded Bobcat fuel shutoff part numbers (reference only)
- Quality inspection record showing coil resistance measurement and plunger stroke test
- Warranty terms covering both electrical coil failure and mechanical seat leakage
- Packing photographs documenting solenoid condition and connector integrity before sealing
- HS code and customs classification for engine auxiliary solenoid components
Installation & Rebuild Sequence
- Verify coil resistance against engine-specific specification before connecting the 12V circuit
- Inspect and clean the solenoid mounting bore to prevent debris from binding the plunger
- Replace fuel line gaskets at the solenoid interface to prevent external seepage
- Test relay contact voltage drop under load to confirm the circuit delivers stable 12V
- Cycle the ignition through several start-shutdown sequences before returning the Bobcat to service
Requesting the Right Engine Auxiliary Package
Provide your Bobcat engine serial number and any previous rebuild history so we can confirm the correct stop solenoid variant and associated fuel system seals. If the nameplate is unreadable, a clear photograph of the existing connector and mounting face allows our technical team to identify the engine family. For fleet maintenance planning, share the machine model list and we will assemble matched auxiliary kits for each engine configuration.
Frequently Asked Questions
Q: What other fuel system components should be replaced alongside the stop solenoid?
A: During a stop solenoid engine rebuild, we recommend replacing fuel line gaskets at the solenoid interface, inspecting the electrical connector for corrosion or heat damage, and checking the upstream relay contacts. These adjacent components often share the same service life and their failure produces symptoms identical to solenoid failure. Shipping them together avoids a second teardown.
Q: How do I confirm the correct electrical specification for my Bobcat engine variant?
A: Provide the engine serial number from the block casting or the machine data plate. Bobcat fitted different engine families across models like the S175 and T190 over successive production years, and the coil resistance specification can differ between them. We cross-reference your serial against the specific auxiliary configuration to verify voltage and connector type.
Q: Could the solenoid failure originate from a wiring or relay fault rather than the part itself?
A: Frequently, yes. A burned stop solenoid coil often indicates a relay with degraded contacts allowing voltage fluctuation, or harness insulation breaking down under vibration. We recommend testing circuit continuity and relay contact resistance before installing the replacement. Installing a new solenoid into a compromised circuit will produce the same failure within weeks.
Q: Can I order a complete engine auxiliary service kit in one consignment?
A: Yes. We consolidate the stop solenoid with fuel filters, line gaskets, mounting hardware, and connector repair components under a single order. This approach eliminates split shipments and ensures all parts for the engine auxiliary service arrive together. Each kit is verified against your specific Bobcat engine serial before packing.
Q: What testing is performed before shipment to verify solenoid function?
A: Every stop solenoid undergoes coil resistance measurement to confirm it falls within the specified range for its voltage rating. The plunger stroke is tested to verify full travel and clean seating against the fuel passage. These results are documented in the quality inspection record that ships with your order, covering both electrical and mechanical performance criteria.