The Honda 39500-ZB7-003 Timer Unit is a genuine OEM component designed for EX3300 and EX4500 generators and the EXW171 welder generator. As a direct Honda OEM replacement, this part is sourced to the same specifications as the original, ensuring correct operation within the generator's ignition and control system. Confirm your model and serial number against the fitment table before ordering, as Honda supersedes parts at specific serial breaks.
Key Features
- Genuine OEM Ignition Timing — sourced directly from Honda, this timer unit controls ignition timing to the same specification as the original, maintaining correct spark delivery and engine cycle management in your generator.
- Direct OEM Replacement — engineered to replace the original unit without adaptation, this part connects and mounts exactly as the factory component did, restoring proper function quickly.
- Broad Generator Fitment — compatible with EX3300 and EX4500 generators and the EXW171 welder generator, including both conventional and welder generator applications.
- Serial Number Verification Recommended — Honda updates part specifications at serial number breakpoints; check your unit's serial number against the fitment table to confirm this is the correct timer unit for your machine.
The timer unit governs when the ignition system fires the spark plug relative to the engine's crankshaft position. By controlling ignition timing, it ensures combustion occurs at the right moment in the engine's cycle, directly affecting power output, fuel efficiency, and smooth running. When the timer unit fails or drifts out of specification, the engine may misfire, run rough, lose power, or fail to start entirely — making it a critical component for keeping your generator or welder generator producing clean, consistent power.
Part Details
| Part Number | 39500-ZB7-003 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Timer Unit |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Generator | EX3300, EX4500 | All |
| Welder Generator | EXW171 | All |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
