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Lean and spark plug

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Hi, I have a quick question. If my stock jetting is running a little lean or rich would using a colder or hotter spark plug help with the conditions?

"For example" In the drz400 owners manual is suggest that if the standard plug "NGKcre8e" is wet in appearance or very dark in color you should use the NGKcr7e plug, and the NGKcr9e plug if the standard plug is glazed appearing or very white. Im assuming these plugs are diuffernet heat ranges that my clear up overly rich and/or lean conditions ?

Any opinions ?

Cheers

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A little off topic but close, is it ever recommended w/drz to go one step colder plug when installing higher c.r. big bores?

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I was thinking more of the increase in c.r. & thinking of detonation etc. In my old air cooled days with bump in c.r. would usually go to one no. colder plug, but you're right, I've never heard Eddie mention it either...thnks

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Detonation is rectifiable by octane. A bump in cr and other mods could make the plug run too hot, esp in an air cooled engine. Water cooling for the most part is able to maintain a consistent plug temp, which is also why reading a plug color is not dependable in a water cooled bike. The variations in color are so subtle, only a expert can identify if a engine could benefit from a different plug. Back in the olden days of a air cooled two stroke, plug chops were use ful as the temp of the plug varied wildly with the mixture and the head did only so much to control the heat. Remember 'Porcupine fins'?

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