6670727 Starter Motor Service Part for Bobcat Excavators & Loaders

Fleet Stocking Plan — Keeping Bobcat compact machines running past the point where factory support thins out.

Technical Specifications

Application Suitability

When Older Compact Machines Outlive Their Supply Chain

A starter motor 6670727 replacement should be on the shelf before the old unit actually fails, not after the machine is already sitting silent on a job site.

Fleet managers running Bobcat compact excavators and loaders often face a frustrating pattern: a machine that has given years of reliable service suddenly refuses to crank on a cold morning. The operator turns the key, hears a slow grind or a dead click, and the equipment is down until a replacement arrives. For older models that have aged out of primary dealer inventories, sourcing that replacement can turn into a multi-week search [NEED_CITE: aftermarket parts availability for aging compact construction equipment]. The downtime cost on a tight urban excavation site or a busy quarry far outweighs the cost of keeping a starter motor in stock. Having seen this pattern repeat across dozens of machines in the Middle East, the lesson is clear—reactive procurement for critical starting components is the most expensive way to buy them.

Where the Starter Motor Sits in the Machine’s Working Life

The starter motor is a high-cycle wear component in any compact machine that undergoes frequent start-stop routines. On a demolition site where the Bobcat E35 or E42 repositions dozens of times per shift, or in a quarry where the S100 loader cycles constantly, the starter motor 6670727 absorbs mechanical and thermal stress with every ignition event. The 10-tooth pinion gear meshes with the flywheel ring gear under load, the solenoid engages and disengages repeatedly, and the internal windings heat up to near their Class H insulation limit. This is not a component that fails randomly—it follows a predictable wear curve tied directly to the number of crank cycles and the ambient conditions in which the machine operates.

Recognizing Wear Before Total Failure Arrives

Most starter motors do not fail without warning. The early signs are measurable and visible if the maintenance team is looking for them. A gradual increase in cranking time, a noticeable drop in engine turnover speed on cold mornings, or an upward drift in current draw toward the 185A maximum all indicate internal degradation. The die-cast aluminum housing with its anodized finish may show heat discoloration near the terminal posts. The pinion gear teeth develop a polished, worn profile that eventually causes incomplete engagement with the flywheel ring gear. Catching these signs during a scheduled service window means the replacement can happen on your timeline, not the machine’s [NEED_CITE: preventive maintenance scheduling for high-cycle electrical components in mobile equipment]. For fleet operators, this is the difference between a planned thirty-minute swap and an emergency that halts production.

Reading the Specifications for Real-World Impact

The 2.2 kW output at 12V places this starter motor in the correct range for the diesel engines found in Bobcat’s compact excavator and loader lineup. The 10-tooth pinion gear with a 20° pressure angle must match the flywheel ring gear precisely—a mismatch in tooth profile leads to grinding, partial engagement, and accelerated wear on both the starter drive and the ring gear itself. The Class H insulation rating to 180°C matters in environments where ambient temperatures already push toward 50°C, as the internal windings add their own thermal load on top. The ±0.15 mm dimensional tolerance ensures the housing registers correctly on the engine block, preventing misalignment that would load the bearings unevenly. The corrosion-resistant anodized finish on the housing is practical insurance against the dust, moisture, and salt air that compact machines encounter across construction, port, and quarry applications.

The Compounding Cost of Reactive Replacement

When a fleet operates without a starter motor in inventory, every failure triggers a cascade of costs that extend well beyond the part itself. The machine sits idle while the team sources a compatible unit, the operator and crew shift to other tasks at reduced efficiency, and the project timeline absorbs the delay. On older Bobcat models like the 325 or 331, where the original supply chain has largely moved on, the search for a compatible starter motor can stretch into days or weeks [NEED_CITE: equipment downtime cost modeling for compact excavator fleets]. Even when a replacement is found urgently, the premium for expedited freight and the risk of receiving an incorrect variant add further cost. Fleet-level thinking means recognizing that the starter motor is not an unpredictable emergency—it is a certainty that will arrive on a known schedule if you track machine hours and crank cycles.

Sourcing That Supports Long-Term Fleet Planning

This starter motor 6670727 is produced on our own selected manufacturing lines and sourced from qualified ISO-certified partners, with both paths carrying the same QC standards and warranty terms. The cross-reference list has been verified to cover superseded and alternate numbers, so buyers working from older parts manuals or worn nameplates can confirm compatibility before ordering. We ship from a Guangzhou warehouse with stock available for fast dispatch on common items, and the minimum order is one piece—meaning a single fleet machine can be covered without forcing a bulk commitment. Our technical team is available to confirm fitment against machine model and serial range, particularly important for Bobcat models where variant differences exist within the same base number. Sample supply is available for fitment confirmation before a fleet-wide stocking decision.

Documentation & Verification

• Commercial invoice and packing list with part number 6670727 and cross-reference sheet marked reference only
• Quality inspection record covering dimensional tolerance, current draw test, and pinion gear engagement check
• Warranty terms document specifying coverage period and manufacturing defect conditions
• Packing photographs showing anti-static foam and reinforced carton before dispatch
• HS code and customs documentation support for international fleet procurement

Service Interval & Stocking Guidance

• Inspect starter motor current draw and pinion condition every 2,000 hours on high-cycle Bobcat excavators
• Stock one replacement unit per three to five machines in fleet to cover predictable failure windows
• Store in dry, temperature-stable conditions to preserve Class H insulation integrity and anodized housing finish
• Record cold-crank amperage baseline at each major service to track degradation trend over machine life

Request a Stocking Recommendation

Provide your Bobcat machine models, current operating hours, and typical duty cycle—whether that is urban excavation with constant repositioning, quarry loading in dusty conditions, or port handling with rapid start-stop routines. We will cross-reference your equipment against the starter motor 6670727 compatibility list and suggest a stocking quantity and replacement schedule aligned to your fleet’s actual usage patterns.

Frequently Asked Questions

Q: How often should a starter motor on a Bobcat compact excavator be replaced?
A: Replacement timing depends on crank cycle count and operating environment rather than a fixed calendar schedule. Machines in high-frequency start-stop applications like demolition or port handling will reach wear limits sooner than those in steady-run tasks. Monitoring cold-crank amperage and cranking speed at each service interval provides a practical wear indicator. Plan replacement when current draw trends consistently upward or cranking speed degrades noticeably.

Q: Should the flywheel ring gear and solenoid be inspected when replacing the starter?
A: Yes. The pinion gear and flywheel ring gear wear together, and installing a new starter motor against a worn ring gear accelerates wear on the replacement unit. The solenoid throw distance should also be verified, as insufficient travel causes partial engagement. These checks take minutes during the swap and prevent premature repeat failure of the new starter motor.

Q: How many starter motors should a rental fleet keep in stock?
A: A practical baseline is one unit per three to five machines of the same model family, adjusted upward for machines operating in extreme heat or high-cycle conditions. Rental fleets with rapid turnover benefit from stocking at the higher end of that range, since unexpected downtime on a rented machine carries both repair cost and customer relationship consequences.

Q: Will compatible starter motors still be available for older Bobcat models like the 325 or 334?
A: The cross-reference list for this starter motor covers multiple superseded and alternate numbers across the Bobcat compact excavator range, including older models. Our verification process accounts for variant differences within the same base number, so compatibility is confirmed against specific machine serial ranges rather than relying on generic fitment tables.

Q: How do you build a preventive replacement plan for high-cycle starter motors?
A: Start by recording a baseline current draw and cranking speed for each machine when a new or known-good starter is installed. Track these values at each scheduled service. When the trend shows consistent degradation, schedule the replacement during the next planned maintenance window. This converts an unpredictable failure into a managed maintenance event.