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G3900-3705030 YUCHAI Natural Gas Ignition Coil
Keep your CNG bus fleet on the route. The G3900-3705030 ignition coil fits Yuchai YC6J and YC6M natural gas engines — the same platforms powering city buses across Southeast Asia, the Middle East, and Africa. Coil-on-plug design means no spark plug wires to replace. RJT PARTS tests every unit and backs it with a 12-month warranty. Send your engine model to info@rjtparts.com — we confirm fitment within 24 hours.
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G3900-3705030 Ignition Coil for YUCHAI YC6J YC6M Natural Gas Bus Engine | RJT PARTS
Product Overview
The G3900-3705030 ignition coil is a coil-on-plug unit designed for Yuchai natural gas engines. It mounts directly on top of each spark plug and delivers the high-voltage current needed for clean combustion. This part fits Yuchai YC6J and YC6M gas engines that power city buses and coaches across Southeast Asia, the Middle East, and Africa.
RJT PARTS supplies the G3900-3705030 coil as a direct-fit aftermarket replacement. It matches the original Yuchai electrical connector and mounting dimensions, so your technician installs it without adapters or wiring changes. Every unit passes bench testing for insulation resistance and spark output before we pack it for shipment.
This coil belongs to a different specification family than the M2C00-3705061. Therefore, always confirm your original part number ends in 3705030 before ordering. The two suffixes are not interchangeable.
Cross-Reference Yuchai Part Numbers
| Yuchai Part Number | Suffix | Engine Platform | Notes |
|---|---|---|---|
| G3900-3705030 | 3705030 | YC6J, YC6M | Primary number for this coil family |
| J5700-3705060A | 3705060 | YC6M gas | Related variant |
| 202V25919-6003 | — | YC6J / YC6M | Cross-reference used by some suppliers |
Important: G3900-3705030 uses the 3705030 suffix. It does not interchange with M2C00-3705061, K1A00-3705061A, or other 3705061 suffix coils. Check your old coil label carefully. If unsure, send us a photo.
Compatible Yuchai Engine Models
| Engine Series | Displacement | Power Range | Common Applications | Fuel | Coils per Engine |
|---|---|---|---|---|---|
| YC6J | 6.5L | 190–245 HP | City buses, school buses, medium coaches | CNG / LNG | 6 |
| YC6M | 10L | 280–380 HP | Heavy coaches, intercity buses, trucks | CNG / LNG | 6 |
Common bus brands using these engines:
- Yutong
- King Long
- Golden Dragon
- Higer
- Ankai
- Sunlong
- Foton
- Yaxing
Diesel YC6J and YC6M engines do not use this part. This coil fits spark-ignited natural gas (CNG/LNG) versions only.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Name | Ignition Coil (Coil-on-Plug) |
| OEM Number | G3900-3705030 |
| Cross References | J5700-3705060A, 202V25919-6003 |
| Engine Make | Yuchai (YUCHAI) |
| Compatible Models | YC6J, YC6M (Natural Gas) |
| Ignition Type | Distributorless, Coil-on-Plug (COP) |
| Input Voltage | 12V / 24V DC |
| Output Type | High-voltage spark |
| Mounting | Direct bolt-on, cylinder head mounted |
| Connector | OEM-matching electrical plug |
| Quantity per Engine | 6 |
| Condition | New, aftermarket |
| Testing | 100% bench tested |
| Warranty | 6-12 months |
| Lead Time | 1–3 days (stock) |
Key Features
- Coil-on-plug design. Mounts directly on the spark plug — no high-tension leads needed.
- YC6J / YC6M specific. Engineered for Yuchai’s 6.5L and 10L gas platforms.
- Dual voltage support. Works with both 12V and 24V bus electrical systems.
- Heat-resistant housing. Epoxy-sealed construction handles high under-hood temperatures in stop-and-go city bus duty.
- Cost-effective. OEM-level performance at a lower aftermarket price point.
Failure Symptoms — When to Replace
- Engine misfire under load or at highway speed
- Check engine light with misfire codes (P0300–P0306)
- Increased gas consumption (higher CNG/LNG usage)
- Rough idle or hesitation on acceleration
- Loss of power on gradients or with full passenger loads
- Visible cracks, carbon tracking, or burn marks on the coil body
- Hard starting, especially in cold morning conditions
Fleet maintenance tip: City buses run constant stop-and-go cycles that stress ignition components. Replace all six coils during a major tune-up to avoid repeated breakdowns. RJT PARTS offers discounted 6-coil engine sets for bus fleets.
Installation Notes
- Disconnect the battery before starting work.
- Remove the engine cover and any intake piping blocking the coil pack.
- Unplug the electrical connector from the faulty G3900-3705030 coil.
- Remove the hold-down bolt and pull the coil straight off the spark plug.
- Compare the old coil with the new unit to confirm matching dimensions and connector orientation.
- Apply dielectric grease to the inside of the new coil boot before installation.
- Seat the new coil and torque the mounting bolt to Yuchai factory specification.
- Reconnect the harness and battery. Clear fault codes and start the engine to verify smooth operation.
Follow Yuchai service manual lockout/tagout procedures for natural gas fuel systems before servicing.
Why RJT PARTS
RJT PARTS supplies engine replacement parts to bus fleets, repair shops, and distributors worldwide. We know that a downed bus costs revenue every hour, so we keep the G3900-3705030 coil and related Yuchai gas engine parts on the shelf.
- Verified fitment. We cross-check every order against Yuchai part catalogs and engine serial numbers.
- Fast dispatch. In-stock orders leave our warehouse within 48 hours of payment.
- Flexible quantities. Order one coil for a repair or a full carton for fleet stock.
- Bulk discounts. Tiered pricing at 10, 50, and 100+ pieces — ideal for bus operators.
- Worldwide shipping. DHL, FedEx, air freight, and sea freight to over 100 countries.
- Technical support. Send your engine nameplate or old part number — we confirm the match within 24 hours.
Custom Product Attributes
| Attribute | Value |
|---|---|
| Supplier | RJT PARTS |
| Part Name | Ignition Coil (Coil-on-Plug) |
| OEM No. | G3900-3705030 |
| Cross Ref. | J5700-3705060A, 202V25919-6003 |
| Engine Brand | Yuchai |
| Engine Model | YC6J, YC6M |
| Fuel Type | CNG / LNG (Natural Gas) |
| Ignition Type | Coil-on-Plug (COP) |
| Voltage | 12V / 24V |
| Qty/Engine | 6 pcs |
| Condition | New Aftermarket |
| Warranty | 12 Months |
| MOQ | 1 pc |
| Shipping | DHL / FedEx / Air / Sea |
| Payment | T/T, PayPal, Western Union, Trade Assurance |
FAQ
Q: Is G3900-3705030 the same as M2C00-3705061?
A: No. They belong to different specification families. G3900-3705030 fits YC6J and YC6M engines, while M2C00-3705061 fits YC6MK, YC6L, and YC6G. The suffixes (3705030 vs 3705061) identify different coil designs. Always match your original part number exactly.
Q: What does “coil-on-plug” mean?
A: Coil-on-plug (COP) means the ignition coil mounts directly on top of the spark plug, eliminating the need for separate high-tension spark plug wires. This design reduces energy loss and improves reliability.
Q: How many coils does a YC6J engine need?
A: The YC6J and YC6M are both 6-cylinder engines, so they use 6 ignition coils — one per cylinder.
Q: Will this coil fit a diesel YC6J engine?
A: No. The G3900-3705030 fits the natural gas (CNG/LNG) version of the YC6J and YC6M only. Diesel engines use compression ignition and do not require ignition coils.
Q: What bus brands use this coil?
A: Yuchai YC6J and YC6M gas engines commonly power Yutong, King Long, Golden Dragon, Higer, Ankai, Sunlong, Foton, and Yaxing buses.
Q: What is the warranty?
A: 12 months from the date of delivery. We replace any coil that fails due to manufacturing defects.
Request a Quote
Need the G3900-3705030 ignition coil for a Yuchai YC6J or YC6M gas bus? RJT PARTS has it in stock and ready to ship. We also supply spark plugs, sensors, and other gas engine consumables for the same engines.
Send your part number, quantity, and destination country to info@rjtparts.com, or message us on WhatsApp for an instant quote. We reply within 24 hours.
📧 info@rjtparts.com
💬 WhatsApp: +86 178 8245 4252
