Starter Motor B7617-3708100 24V 8KW 11T Yuchai YC6B125

Product Overview

The B7617-3708100 is a Yuchai OE-spec replacement starter motor delivering 24V 8KW starting output with an 11-tooth drive gear, engineered for Yuchai YC6B125 (6108 platform) diesel engines. This aftermarket unit matches the original starting-system specification for the Yuchai 6108 engine platform.

Fitted with solenoid shift design, this brand-new starter motor is stocked in-house with a 1-year warranty and 10-day dispatch lead-time. The factory-correct 8KW power rating is matched to the cranking demand of Yuchai 6108 diesel engines, supporting reliable cold-start cranking and consistent ring-gear engagement.

Key physical specs: net weight 9.7 kg, gross weight 10.15 kg, overall dimensions 440 x 240 x 190 mm, supplied inside neutral kraft inner carton.

The Yuchai YC6B125 6108 Platform and 24V Starting System

The Yuchai YC6B125 belongs to the Yuchai 6108 family of six-cylinder diesel engines, widely fitted in trucks, buses and construction and agricultural machinery across China and export markets. These engines use a 24V starting system with starter motors rated at 8KW and an 11T drive gear, sized to deliver reliable cold-start cranking under heavy-duty operating conditions.

It is critical to verify the voltage, power rating and tooth count on your old starter: this unit is rated at 24V 8KW with an 11T drive gear. Starters with a different voltage, power rating, tooth count or mounting pattern are not interchangeable with this unit. The 11T drive gear is a key identification point for this unit, so count the teeth on your old starter pinion carefully.

Confirm the mounting flange pattern, terminal positions and connector configuration against your original starter before ordering. Always cross-check the OE numbers stamped on your old unit, including the B7617-3708100 family, before placing an order.

Technical Specifications

Compatibility and Cross Reference

According to the original product page, this starter motor fits Yuchai 6108 engines, covering the YC6B125 application. The original page does not publish a detailed fitment table, so do not rely on the engine name alone for fitment validation; always compare the original part number, mounting holes, tooth count and connector configuration before ordering.

If your original unit bears one of the listed cross-reference numbers, B7617-3708100 serves as a direct drop-in replacement.

What to Look for in a Replacement

Follow these five verification steps before placing your order to avoid wrong-part returns:

• 1. Check the voltage and power rating on your old starter: confirm it is a 24V 8KW unit for the Yuchai 6108 application. Other ratings are not interchangeable.

• 2. Check the tooth count on your old starter: confirm it is an 11T drive gear. Starters with a different tooth count are not interchangeable.

• 3. Confirm the application is a Yuchai YC6B125 (6108 platform) diesel engine. Other engine families may use different starter assemblies.

• 4. Compare the mounting holes, flange pattern and connector configuration with your original starter, and match OE numbers including the B7617-3708100 family.

• 5. Weight cross-check: genuine matching unit weighs approximately 9.7 kg net; significant weight difference indicates wrong assembly.

Application Scenarios

• Heavy-duty vehicle repair shops servicing Yuchai 6108 powered trucks, buses and machinery with failed starting systems.

• Fleet maintenance teams for buses, trucks and construction machinery replacing worn 24V starters.

• Auto parts retailers and distributors stocking Yuchai engine starters for the aftermarket.

• Vehicle owners and DIY technicians replacing worn starters with a factory-spec new unit.

• Exporters supplying Yuchai and Chinese commercial-vehicle starter motors to global markets.

FAQ

Q: Which engines does this starter motor fit?
A: It fits Yuchai YC6B125 diesel engines of the 6108 platform. Confirm your exact engine model and OE number before ordering, and check that your old starter is a 24V 8KW 11T unit.

Q: My old starter shows number QDJ2709, will B7617-3708100 work?
A: Yes. QDJ2709 is the cross reference number of the same starter family for the Yuchai 6108 application, differing only by production revision and market specification. It serves as a direct replacement.

Q: What does YC6B125 refer to?
A: YC6B125 is the Yuchai engine model code, not a starter part number. It identifies the 6108-platform six-cylinder diesel engine that this starter is engineered for.

Q: My old starter has 10 or 12 teeth, will this 11T unit fit?
A: No. The tooth count must match: this unit has an 11T drive gear, and a starter with a different tooth count is not interchangeable. Confirm the tooth count of your old starter before ordering.

Q: What is your warranty and lead-time?
A: Goods are in stock with a 10-day dispatch lead-time. A 1-year warranty applies from installation date; warranty excludes damage caused by mis-installation, incorrect wiring, water ingress, short circuit or physical damage.

In Practice

The original product page does not publish a specific installation method or torque data for this starter. The following section therefore uses the general 24V starter installation standard, with reference to the common installation practice for Yuchai 6108 starters and after-sales maintenance experience from the heavy-duty repair industry; before installation, compare the specific torque values with the corresponding Yuchai service manual.

Disconnect the negative battery cable first to prevent short circuit and electric shock during installation. Remove the starter mounting bolts, disconnect the B+ main cable and the S control wire from the solenoid terminals, and mark them for reconnection. Take out the old starter smoothly, and inspect the flywheel ring gear for chipped or worn teeth; replace the ring gear if damaged. Clean the flywheel housing mounting surface and the starter flange, free of oil stains, rust and burrs.

Align the new starter with the flywheel housing spigot, insert the mounting bolts and hand-tighten, then tighten in a diagonal sequence in 2-3 steps with a torque wrench; for 24V starters, a typical reference torque for the main mounting bolts is 55-65 N.m, to be fine-tuned with reference to the corresponding Yuchai model manual. Connect the S control wire to the solenoid S terminal, then connect the B+ main cable to the battery positive terminal, tightening the nut securely. Ensure the starter housing is grounded through the mounting bracket, free of rust and oil stains. Secure the wire harnesses to avoid contact with hot exhaust components and moving parts.

After installation, reconnect the negative battery cable and check the wiring connections. Start the engine and check that the starter engages smoothly and the pinion returns fully after starting. Each single start-up shall not exceed 5 seconds, with an interval of at least 10-15 seconds between consecutive start-ups to avoid overheating. If the starter fails to crank, check the battery voltage (at least 24V under load), the main cable connections and the solenoid operation before further testing.

References

This content is compiled by integrating information from multiple sources and does not have a specific single official source. The original product page does not publish a specific installation method or official torque data for this starter. The installation method and torque reference values in this article are summarized and integrated based on the universal installation standards for 24V starters, the common installation practice for Yuchai 6108 starters, and practical experience from the mainstream heavy-duty repair industry, verified against actual installation tests and after-sales maintenance experience; for vehicle-specific torque values, please refer to the corresponding Yuchai service manual.

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