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Easiest way to tell if my DRZ has already been jetted

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So I bought my 07 Drz400s with 3k miles, really clean bike but I bought it off the second owner who didn't ride it and he didn't know anything about the upgrades.. It already had a power bomb header and power core 4 slip on, and the carb has definitely been apart before by the look of the screws on it, but I see the air box hasn't had the 3x3 cut out of it yet. So I'm wondering what would be the easiest way to check and see if I need to just cut the hole or if I need to just order the JD kit and cut the hole.. either way I want the bike to have the mod done. Any advice it much appreciated!

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How is the jetting?  Proper jetting is all about throttle response. If you are pleased with the throttle response, don't worry about what is installed. But to answer the question, the only way to know what jets are installed is to look at them. 

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How is the jetting?  Proper jetting is all about throttle response. If you are pleased with the throttle response, don't worry about what is installed. But to answer the question, the only way to know what jets are installed is to look at them. 

Throttle response is very good and the bike runs excellent.. but if the bike has a little more to offer, I'd like to take advantage of it, especially since somebody already put full exhaust on it. I figure I can spend $100 and kinda maximize what that exhaust has to offer, especially since I didn't pay any extra for it having it on there since the guy didn't even know what it was..

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Allen bolts holding on the float bowl instead of screws is a good sign because the kits come with the bolts cause the screws strip 

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take the carb off the bike and look... it really only takes 10 minutes to do it....

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 Pull the sparkplug and see if it's burning rich or lean, if the plug is on the black side, do your 3x3

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9 hours ago, ajdino said:


Throttle response is very good and the bike runs excellent.. but if the bike has a little more to offer, I'd like to take advantage of it, especially since somebody already put full exhaust on it. I figure I can spend $100 and kinda maximize what that exhaust has to offer, especially since I didn't pay any extra for it having it on there since the guy didn't even know what it was..

If the throttle response I good, you will not make any additional power by upsizing a jet or moving a needle. More than likely you go to the rich side and begin to loose power. 

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 Pull the sparkplug and see if it's burning rich or lean, if the plug is on the black side, do your 3x3

That's a good idea, I have a new plug to throw in her anyways, so that might be my first step..
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If the throttle response I good, you will not make any additional power by upsizing a jet or moving a needle. More than likely you go to the rich side and begin to loose power. 

So with the full open exhaust, are you saying if the bike is still very responsive that re-jetting and giving more air wouldn't necessarily up my power/acceleration ? Assuming it still has its stock jetting.. the bike runs great, just heard that the 3x3 mod really wakes it up.. just don't want to be running the exhaust the bike needs but not giving it the fuel/air it needs to maximize what the exhaust can handle putting out..

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Bikes come from the factory jetted too lean and performance can be improved with proper resetting. In additional, opening the airbox may require that the needle be raised one position. A free-flow exhaust normally requires a larger main jet. There are a lot of threads on every motorcycle site regarding throttle position and the jets that are effected. See if you have a smooth transition from these throttle positions at both a slow and fast roll-on. If you do, then make no changes. 

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Just now, RC_ichard said:

Why not just Pull the carb and look at the jet stamps... or am I missing something in your question?

Haha, tht's what I said, lol

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If the needle has more then on clip position... it's been jetted to some extent.

Main or pilot jet differs from stock... it's been jetted to some extent.

Float bowl screws alen.... it's been opened but could have just been cleaned.

Fouling and lean conditions... again not a tell tail. 

Only way to know 100% is to remove seat, tank, and pull carb (ok... and maybe loosen sub frame too if you were not good at tetris growing up and need a little extra room)

Anything else will be pretty much speculation. Good luck!!

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If the needle has more then on clip position... it's been jetted to some extent.
Main or pilot jet differs from stock... it's been jetted to some extent.
Float bowl screws alen.... it's been opened but could have just been cleaned.
Fouling and lean conditions... again not a tell tail. 
Only way to know 100% is to remove seat, tank, and pull carb (ok... and maybe loosen sub frame too if you were not good at tetris growing up and need a little extra room)
Anything else will be pretty much speculation. Good luck!!

Well, guess I'll just pull the carb out and see what it looks like after work tomorrow.. thanks for the info on what to look for!

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