OTOHANS AUTOMOTIVE Wiring Harness Kit for 4-Stroke 50–125cc ATVs & Pit Bikes — Black, Complete Ignition/Charging/Start Assembly

A complete black wiring harness kit from OTOHANS AUTOMOTIVE that replaces ignition, charging and start components for 4-stroke 50–125cc ATVs and pit bikes.

This all-in-one electrical assembly bundles the main wiring loom with ignition, charging and starting parts so you can restore or upgrade the electrical system on compatible 4-stroke small-displacement ATVs, quads, scooters, go-karts and dirt bikes. The kit is built to be a plug-and-play replacement for many 50cc through 125cc engines (not compatible with GY6 style engines) and includes the key components technicians commonly swap when troubleshooting no-start, charging failures, or intermittent electrical faults.

What parts are included and why they matter?

The kit groups every essential electrical component you need for a standard wiring replacement—saving time sourcing separate pieces. Each part performs a specific role in ignition, charging, and starting so the system works as a coordinated unit.

• Wiring harness loom — the main cable assembly routing power and signals across the vehicle.
• CDI (5-pin) — controls ignition timing for the 4-stroke engine’s spark delivery.
• Solenoid relay — handles high-current switching for the electric start circuit.
• Rectifier / voltage regulator — converts AC to DC and stabilizes charging voltage.
• Ignition switch with two waterproof keys — provides secure power-on control and theft deterrence.
• Start button plug, ignition coil with lead, and a spark plug — key parts for initiating and sustaining combustion.

How easy is installation and what should I check first?

Installation is straightforward for experienced mechanics; the harness is meant to replace factory wiring using the included connectors. If you are unfamiliar with vehicle electrical systems, professional installation is recommended to avoid damage or incorrect connections.

• Compare the supplied wiring diagram to your vehicle’s original layout before beginning.
• Verify engine type—this kit is not for GY6 engines.
• Disconnect the battery and follow proper grounding and polarity procedures.
• Double-check pin assignments on the CDI and connectors during replacement.

Which vehicles and engines will this harness fit?

This harness was designed for a wide range of 4-stroke small-displacement machines, including ATVs, dirt bikes, quads, scooters and go-karts within the 50cc–125cc range. Fitment still depends on model-specific connector layouts and mounting points.

• Compatible: 50cc, 70cc, 90cc, 110cc and 125cc 4-stroke ATVs, dirt pit bikes, quads and some scooters/go-karts.
• Commonly used with Kawasaki KLX style and Coolster-type chassis where wiring layouts match.
• Not compatible with engines using the GY6 electrical design—verify before purchase.
• Includes waterproof ignition switch for wet or off-road use.

What maintenance or safety tips should I follow after installation?

After installing the harness, perform a full electrical check and secure all cables away from heat and moving parts. Proper routing and protective sleeving will prevent chafing and premature failure during off-road use.

• Secure connectors with zip-ties and ensure no wires rub on the frame or exhaust.
• Inspect the spark plug and coil connections after initial running for tightness and correct gap.
• Test charging voltage at idle and with headlight load to confirm regulator operation.
• Replace any damaged clips, fuses, or mounts to maintain reliable performance.

Who is this for? This OTOHANS AUTOMOTIVE wiring harness kit is aimed at DIY mechanics, repair shops, restorers, and riders who need a comprehensive electrical replacement for 4-stroke 50–125cc off-road vehicles. It’s especially useful when diagnosing combined ignition and charging issues, performing engine swaps, or restoring older machines where the original loom or components are corroded or missing. If you’re unsure about compatibility or wiring details, consult a qualified mechanic or contact OTOHANS AUTOMOTIVE for guidance before installation.