Plug colour reading - good diagnostic image

[Jaluka]

Hey chaps found this good image that may be helpful for others in determining where to read colours on the plug for jetting or timing issues.

It confirms what JustKDX's guide says in reading colour at base of porcelain with magnifying glass and torch, also to a lesser degree the flat surface where the threads end...... (for jetting readings)

It was off a jetski website but can also be used for our wheeled fun machines

[husley]

Excellent

Thank you

[Brian VT]

Thanks ! Should come in handy.

[lankydoug]

Great bit of info, thanks for posting. I'm going to share this.

[Bryan]

Very good drawing!

[Bailey28]

I think the deposits left on the "flat surface" at the end of the threads is oil and fuel additive related.

Using the same jetting combo, if I ran Citgo sea and snow or Repsol synth2t, the "flat surface" would be brown. With Yamalube 2R, same jetting and mix ratio, the flat surface is totally clean. The piston top is also totally clean, with only a small heart shaped carbon deposit.

The center of the electrode is dark brown. Bike runs perfect.

[lankydoug]

Originally Posted by Bailey28

I think the deposits left on the "flat surface" at the end of the threads is oil and fuel additive related.

Using the same jetting combo, if I ran Citgo sea and snow or Repsol synth2t, the "flat surface" would be brown. With Yamalube 2R, same jetting and mix ratio, the flat surface is totally clean. The piston top is also totally clean, with only a small heart shaped carbon deposit.

The center of the electrode is dark brown. Bike runs perfect.

While running Sunoco 110 and Spectro SX platinum @ 40:1 the areas that were supposed to be brown were kind of a greenish gray. I switched to VP110 and Lucas synthetic blend @ 36:1 and it's now light brown.

Without turning this in to an oil thread what 2t oil have you found to keep the PV the cleanest?