Best Spark Plugs for Yamaha r6

Best Spark Plugs for Yamaha r6

It is good practice to change out your spark plugs regularly. Here are some of the best spark plugs you can consider.

The best spark plug will be the default spark plugs, which are the NGK CR10EK. They have been proven to have better fuel efficiency and improved combustion ratio. They also work well with your R6 and they cost cheaper than the iridium spark plugs.


Ngk cr9ek vs cr10ek

Note that for these plugs, newbies might get confused between a cr9ek and a cr10ek.

The main difference is that a cr9ek will run hotter than a cr10ek. The cr9eck will give you slightly more power but runs the risk of burning a hole at the top of your cylinder. It will also last longer than a cr10ek.

For R6, it is recommended that you use a 10ek, especially for new R6 models, as a cr9ek might be too hot for your bike. That being said, I know older year models such as those form 2004 has a cr9ek spark plug as the default.

There are 2 exceptions to this rule though.

  • One is if you are riding in a cold country. In that case, a cr9ek might be the best spark plug recommendation for your R6.
  • Second is if you are using a higher octane fuel. Such fuel has more alcohol content and hence requires a high ignition point. In this case, a hotter spark plug can help.

Ngk spark plugs vs Denso vs Bosch

Besides the Ngk cr9ek or cr10ek, there are brands in the market that also produces similar copper based spark plugs. These brands are

  • Denso U27ESRN
  • Autolite 4302
  • Bosch UR2CC
 Lets do a comparison between each of them.

Ngk vs Denso spark plugs (motorcyle)

The main difference is that a Ngk spark plug is more durable and affordable than the Denso spark plug. While some say the Denso spark plug can deliver a more powerful burst of power, this is not a uniform experience. However, Yamaha R1 has adopt Denso as its stock spark plug.

The Denso spark plug has a narrower electrode so it needs more careful handling compared to the Ngk, with its thicker electrode.

In summary, I would suggest sticking to the Ngk brands for your R6, given it is cheaper and has no disadvantage to the Denso.


Ngk vs Bosch spark plugs (motorcyle)

The main difference between Ngk and Bosch is reliability. Ngk spark plugs have been proved by countless R6 riders that they work with out no issue. In contrast, Bosch spark plugs have created issues such as exploding plugs. Both spark plugs cost similar to each other.

I scan through countles R6 forums and have nobody has any nice things to say about Bosch spark plugs. The only conclusion that can be drawn is they are not as good fit for the R6 bikes, thus resulting in issues that no other bike or car owner bought out.


Ngk iridium park plugs vs normal

A common consideration is whether to use stock spark plug or upgrade to an iridium spark plug.

The biggest difference is that a ngk iridium spark plug has a much harder metal element than a normal spark plug. This makes iridium spark plug more wear resistance, have a longer shelf life and a better combustion performance. The last advantage is due to iridium having a higher melting point but is still up for debate.

However all these comes at a high price. A iridium spark plug costs 5 times more than a normal one. Hence, even with its longer durability, you have to ask if a iridium spark plug justify its cost?

Also, there is one disadvantage with not changing your spark plug regularly – they become more difficult to replace as they seized onto the threads. When you forcefully change them, the threads might be damaged and need to replaced, which is another cost.

Finally,  if you cannot replace your plugs and need external help, then you also need to factor in this servicing cost. Since iridium spark plugs need less replacement, they will require less servicing cost.

How to change the spark plugs in your R6 motorocycle

One thing to note is that a normal torque wrench might not work because it is difficult to squeeze that into the right positioning. Look for one that has pivot points so that it can get to the tight points.

When you are ready to change the spark plugs, here are the steps:

  • Lift the tanks. You don’t need to drop the radiator as the angles of the plugs are such that they are not blocked by it.
  • There are 4 plugs to change. The first 2 can be easily changed with the torque wrench.
  • Before you go in for the third plug, remove the vacuum lines. Be careful not to break the case vacuum.
  • At at the last plug, you need to remove ram air tube first to make room.
  • After removing the air tube BUT before taking the plug out, use a air compressor to blow out any dirt inside the hole. Doing so will prevent dirt from dropping into the cyclinder when you remove the plugs.
  • Remove the plug
  • Put in all the new plugs and back the stuff you have taken out like air tubes and the vacuum lines. Again, be careful with the vacuum case.



To conclude, the best spark plugs for Yamaha R6 is simply its default spark plugs, which are the Ngk cr9ek or the Ngk cr10ek. There is a reason why they are the factory default. They are simply more reliable and are compatible with the engines of the R6.

The only major change you have to consider is whether you want to upgrade to a iridium spark plug. While they are more durable, they also more expensive so the cost saving might not be all that great. In terms of performance, it is not significant enough that all riders can agree that it is an improvement.

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