CrankDex

Yamaha XS400 Spark Plug

The Yamaha XS400 (346cc) takes an NGK BR9ES spark plug, gapped to 0.032".

Shop the BR9ES plug Amazon · we may earn a commission, at no extra cost to you

Key takeaways

  • Spark plug: NGK BR9ES.
  • Iridium upgrade: NGK BR8EIX.
  • Gap: 0.032 inch - set it before fitting.
  • Covers 2003-2009.
Standard PlugBR9ES
Iridium UpgradeBR8EIX
Gap0.032"
Verified fitLast checked
Sources: NGK powersports application catalogue
Reviewed by the CrankDex editorial team against manufacturer and retailer fitment data.

Buy the plugs for your Yamaha XS400

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.

Shop the BR9ES plugStandard NGK plug + multi-packsShop Upgrade: BR8EIX iridiumLonger life, stronger sparkShop

As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.

Frequently asked

What spark plug does a Yamaha XS400 take?

The Yamaha XS400 takes an NGK BR9ES spark plug, gapped to 0.032 inch. The iridium upgrade is the BR8EIX.

What is the spark plug gap for a Yamaha XS400?

The spark plug gap for the Yamaha XS400 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 XS400?

Yes. The BR8EIX 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 XS400

We cover the other consumables for your machine too - the exact fit, cited, in one place.

Batteryfor the XS400Air & oil filterYamaha air & oil filtersTire sizeYamaha tire sizes

More Yamaha spark plugs

0.035 250 RT3AT1AT1BMXAT1CMXAT2AT2MAT2MXAT3BW350CP250 Morphous ScooterCS3BCS5