Yamaha MX400 Spark Plug
The Yamaha MX400 takes an NGK BR9ES spark plug, gapped to 0.032".
Key takeaways
- Spark plug: NGK BR9ES.
- Iridium upgrade: NGK CR8EIX.
- Gap: 0.032 inch - set it before fitting.
- Covers 1980.
Buy the plugs for your Yamaha MX400
The standard plug is the exact-fit replacement. The iridium version drops into the same spot, lasts longer, and fires a little stronger for a few dollars more. Many engines take more than one - check how many cylinders you have.
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Frequently asked
What spark plug does a Yamaha MX400 take?
The Yamaha MX400 takes an NGK BR9ES spark plug, gapped to 0.032 inch. The iridium upgrade is the CR8EIX.
What is the spark plug gap for a Yamaha MX400?
The spark plug gap for the Yamaha MX400 is 0.032 inch. Check and set the gap before fitting a new plug - most powersports plugs need a small adjustment out of the box.
Can I use an iridium plug in a Yamaha MX400?
Yes. The CR8EIX is the iridium version of the BR9ES - same fit, longer life, and a slightly stronger spark. It is a straight upgrade.
More parts for your Yamaha MX400
We cover the other consumables for your machine too - the exact fit, cited, in one place.