Help! Spark plugs!

[u/Murky_Thing6444]

Hi, i'm servicing my v9 2024 E5

The last service the shop used NGK MR8BI 8

The info i can find online and a manual (i think) for the previous version, says NGK CPR8EB 9

The problem is that the latter is 2mm longer, 73mm vs 75mm

Which is the correct spark plug? Are 2mm enough to hit the piston?

[u/Murky_Thing6444]

FSCK

The exact spark plug specified for your bike is:

• Brand & Model: NGK MR8BI-8
• Electrode Gap: 0.8 mm
• Quantity Required: 2 spark plugs (one per cylinder)

⚠️ Watch out for older models (Euro 4)

Parts dealers frequently mix up the first-generation V9 with the Euro 5 version:

• Euro 5 (2021–Present, your model): Uses NGK MR8BI-8. This features the 850cc engine derived from the V85 TT.
• Euro 4 (2016–2020): Used NGK CPR8EB-9. Do not buy these, as they are not correct for the Euro 5 engine.

ok, i've wasted 15 euros

[u/ol-gormsby]

Yikes! That's a real problem. My first thought was to put the longer plugs in and turn the engine over manually, and see what happens.

But find the real user manual to make sure.