NGK BR8ES Spark Plug | Honda CB350 / CB360 / CB450 / CB500T
The NGK BR8ES is the correct spark plug for the Honda CB350, CL350, SL350, CB360, CL360, CJ360, CB450, CL450, and CB500T. This copper-core resistor plug is the direct replacement for the discontinued B8ES. Sold individually — you need two plugs per bike.
Specifications
| Replaces OEM | 98079-58840, 98079-58810, 98079-58840-S, 98079-58860 |
|---|
| Fits Models | CB350 / CL350 / SL350 (1968–1973), CB360 / CL360 / CJ360 (1974–1977), CB450 / CL450 (1965–1974), CB500T (1975–1976) |
|---|
| Plug Type | NGK BR8ES — Copper Core, Resistor |
|---|
| Gap | 0.7–0.8 mm (0.028–0.032 in.) |
|---|
| Qty | Sold Individually (need 2 per bike) |
|---|
B8ES vs. BR8ES — What Changed?
As of January 2020, NGK discontinued the B8ES and replaced it with the BR8ES. The "R" designates a built-in resistor that reduces electromagnetic interference (EMI) from the ignition system — useful if you run a phone mount, GPS, or radio on your bike. The BR8ES performs just like the B8ES for combustion and is the correct replacement for all Honda twins listed above.
Gap and Installation
Set the gap to 0.7–0.8 mm (0.028–0.032 in.) using a spark plug gap gauge before installation. Apply a small amount of oil to the threads and hand-tighten until snug.
Terminal nut vs. terminal stud: The BR8ES ships with a terminal nut installed. If your spark plug boots need a terminal stud, unscrew the nut with pliers to expose the stud threads underneath — it can be extremely tight. See our terminal nut vs. stud guide for details.
Reading Your Spark Plugs
After running the engine, pull the plugs and check the tip color to assess engine condition:
- Light tan to chocolate brown — normal, healthy mixture
- Black carbon deposit — rich fuel mixture, dirty air filter, or prolonged idling
- Oil fouling (wet tip) — worn piston rings or valve guides
- White crust — lean fuel mixture or plug heat range too hot
Copper-core plugs like the BR8ES are ideal for carburetor tuning — keep extras on hand so you can read the mixture on a fresh plug.
Frequently Asked Questions
Why won't my spark plug boot fit on the new plug?
Unscrew the terminal nut on top of the plug to expose the terminal stud. The boots connect to the stud, not the nut. Use pliers — it can be very tight. See our terminal nut vs. stud guide.
Is the BR8ES the same as the B8ES?
Yes, for combustion purposes. NGK discontinued the B8ES in January 2020. The BR8ES is the direct replacement — the "R" adds a built-in resistor for EMI reduction, but heat range and gap spec are the same.
What gap should I set?
0.7–0.8 mm (0.028–0.032 in.) for all supported models — CB350, CL350, SL350, CB360, CL360, CJ360, CB450, CL450, and CB500T.
Does this plug fit the CB500K or CB550?
No — the CB500K and CB550 inline fours use the NGK D7EA. The BR8ES is for Honda twins only.
You Might Also Need
Last updated: March 2026
