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Question on JD and jets...

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Hi everyone,

I have done a search on this but couldn't find any help. I have a few questions and hope that fellow TT members would shared it with me. 😢

Q1 What the different between the JD red and blue? What will happen if i install the blue instead of the recommended red? 😢

Q2 What does the pilot air jet do in the FCR? What happen if there's more air or less air?

Q3 Any good sites that shows the colour of the plug from a properly tuned bike?

I thanks in advance to whoever that could share your knowledge.

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Hi everyone,

I have done a search on this but couldn't find any help. I have a few questions and hope that fellow TT members would shared it with me. 😢

Q1 What the different between the JD red and blue? What will happen if i install the blue instead of the recommended red? 😢

Q2 What does the pilot air jet do in the FCR? What happen if there's more air or less air?

Q3 Any good sites that shows the colour of the plug from a properly tuned bike?

I thanks in advance to whoever that could share your knowledge.

The difference is in the taper of the needle. The red is leaner,, and used for higher elevations. The explanations for when to use each is contained in the jetting kit,, and many here can assist once you install, ride, and give us some details.

The pilot air jet is partly responsible for setting the mixture when the needle is lowered,, and the carb is running primarily off the the pilot circut.

More air, leaner pilot circut.

If your running pump gas,, forget plug color.

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The difference is in the taper of the needle. The red is leaner,, and used for higher elevations. The explanations for when to use each is contained in the jetting kit,, and many here can assist once you install, ride, and give us some details.

The pilot air jet is partly responsible for setting the mixture when the needle is lowered,, and the carb is running primarily off the the pilot circut.

More air, leaner pilot circut.

If your running pump gas,, forget plug color.

Hi bronco78,

Pump gas as in accelerator pump? Why is it so?

Thank for the rest of the info

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Does that mean all my plug reading i have done is useless??? 😢

Can i say that as long as the bike do not bog off idle, no hesitation when accelerating, no surge, responsive, pops abit when engine braking, occassional backfires and the plug reads more white, it is still well tuned and no adjustment is necessary...

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Does that mean all my plug reading i have done is useless??? 😢

Can i say that as long as the bike do not bog off idle, no hesitation when accelerating, no surge, responsive, pops abit when engine braking, occassional backfires and the plug reads more white, it is still well tuned and no adjustment is necessary...

OK my experience, and take on plug reading.

Nobel, Burned, others feel free to chime in, add , or correct as you see fit.

1: The additives in todays pump gas deposit on the plug and make it difficult at best to "read" the current fuel/air mixture

2: Very few people who do plug checks do so in a way that will show consistency. ie fresh plug, wide open blast, kill bike coast to stop.. check plug

3: Pump gas, is a huge variable,, from tank to tank.. due to the supplier, time of year, length of time it has been in storage, contamination factor, formulation, and a host of other things.. Meaning,, unless you compare plug readings from the same batch, age, temp, supply. Your seeing those variables on the plug.

4: Yes you can still look at a plug and see if you are grossly rich, lean, have preignition, ect. But the fine tuning of air fuel mixture that was done in years gone by,,is not a great tool any longer when using todays pump gas.

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OK my experience, and take on plug reading.

Nobel, Burned, others feel free to chime in, add , or correct as you see fit.

1: The additives in todays pump gas deposit on the plug and make it difficult at best to "read" the current fuel/air mixture

2: Very few people who do plug checks do so in a way that will show consistency. ie fresh plug, wide open blast, kill bike coast to stop.. check plug

3: Pump gas, is a huge variable,, from tank to tank.. due to the supplier, time of year, length of time it has been in storage, contamination factor, formulation, and a host of other things.. Meaning,, unless you compare plug readings from the same batch, age, temp, supply. Your seeing those variables on the plug.

4: Yes you can still look at a plug and see if you are grossly rich, lean, have preignition, ect. But the fine tuning of air fuel mixture that was done in years gone by,,is not a great tool any longer when using todays pump gas.

Wow, i didnt realized that things has changed so much... Although it a pain to remove the plug from the DRZ, i am always looking forward to reading the plug... you never know what you gonna get...

Thanks bronco78

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Gosh I hate to be so agreeable, but I agree with Bronco too. Well said.

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