Yamaha MX100 Spark Plug
GarageDex's powersports data shows the Yamaha MX100 uses a BR7HS-10 spark plug, gapped to 0.024", or upgrade to the BR8HIX iridium plug.
Spark plug fitment by year
| Years | Standard plug | Iridium upgrade | Gap |
|---|---|---|---|
| 1974-1975 | BR7HS-10 | BR8HIX | 0.024" |
Match the exact part code, thread reach, and heat range. The iridium column is the same-fit upgrade for a longer service life.
Spark plugs for your Yamaha MX100
The recommended plug is a BR7HS-10. Match that code - spark plugs are thread-, reach-, and heat-range-specific, so the part number matters more than the brand. Worth considering: the BR8HIX iridium upgrade - it fits the same port, fires cleaner, and lasts far longer between changes.
As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
Frequently asked
What spark plug does a Yamaha MX100 take?
GarageDex's powersports data shows the Yamaha MX100 uses a BR7HS-10 spark plug, gapped to 0.024", or upgrade to the BR8HIX iridium plug.
What is the spark plug gap on a Yamaha MX100?
The Yamaha MX100 spark plug gap is 0.024". Set the gap with a feeler gauge before install - iridium plugs come pre-gapped but always verify, since a wrong gap causes misfires and hard starts.
Are iridium spark plugs worth it on a Yamaha MX100?
The BR8HIX is the iridium upgrade for the standard BR7HS-10. It fits the same port and heat range, fires more reliably, and lasts far longer between changes - a worthwhile swap for most riders, though the standard plug is perfectly fine if you change plugs on schedule.
How often should I change the spark plugs on a motorcycle?
Standard plugs typically want replacing every 8,000-12,000 miles (or per your service manual); iridium plugs go much longer. Fouled or worn plugs cause hard starts, misfires, and poor fuel economy - a cheap part that punches above its weight.