The PW50 typically uses a standard NGK spark plug; the exact part number varies by year and market. Common options include NGK BR8HS or B6HS (and their resistor variants BR8ES, B6ES). Always verify with the owner’s manual or by inspecting the plug currently installed.
Understanding the PW50 and its spark plug needs
The Yamaha PW50 is a small, air‑cooled, two‑stroke minibike designed for new riders. Its compact engine requires a plug that can handle rapid heat cycling and lean mixtures typical of two‑stroke operation. Because the PW50 has seen various revisions across years and regions, the exact plug type can differ, making it important to confirm the correct heat range and whether a resistor plug is required for EMI considerations.
Common spark plug options by PW50 model year
Use this guide to pick a compatible plug if you don’t have the manual handy. The PW50’s spark plug needs can shift by year or market, but the options below cover the most commonly used plugs.
- NGK B6HS — a common non-resistor plug used on older PW50 models (roughly 1990s). If your bike uses a non‑resistor plug, this is a frequent choice.
- NGK BR6HS — resistor-equipped variant for models that require a resistor plug to reduce EMI.
- NGK BR8HS — a widely used resistor plug for mid‑range heat, common on many PW50s from late 1990s to early 2000s.
- NGK B8HS — a colder/high‑heat option used on some later models or in hotter climates depending on fuel mix and tuning.
- Denso W20ER‑U (and NGK equivalents) — cross-reference for markets where Denso is standard; ensure the thread size and reach match.
Note: The exact number (B6, B8, BR6, BR8, etc.) depends on model year and regional variations. Always confirm with your bike’s manual or by checking the current plug type that’s in service.
How to choose and install the spark plug on a PW50
Follow these guidelines to select the right plug and install it correctly. If you’re unsure, consult a dealer or the PW50 service manual.
- Identify the correct plug by checking the owner’s manual or the plug currently installed on the bike.
- Choose a spark plug with the correct heat range for your climate and tuning (often BR8HS or B6HS for many PW50s).
- Use a proper spark plug wrench to remove the old plug; inspect the threads and gasket seat for damage.
- Set the gap to the manufacturer’s specification (commonly around 0.6–0.7 mm or 0.024–0.028 in).
- Thread the new plug by hand to avoid cross‑threading, then tighten to the recommended torque in the service manual.
- Reinstall any components you removed, reconnect wires, and test start the engine in a safe area.
With the right plug, the PW50 should start reliably, idle smoothly, and perform consistently across riding conditions.
Summary
The PW50 generally uses a small NGK spark plug, with a range of heat‑rated variants available depending on year and market. Common choices include B6HS/BR6HS and B8HS/BR8HS, plus resistor versions like B6ES/BR6ES or BR8ES. Always verify against your specific model and region, and consult the service manual if in doubt.