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DRZ 400 S High altitude richness problem without jetting

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Question.. I live a 5000 feet altitude in very DUSTY conditions, my DRZ runs rich (stock).. I was hoping not to re-jet the bike nor drill the air box.  A mechanic at a local shop suggested put FMF Q4 slip on and a free flow drop in filter and the bike should lean out and run better with out rejetting. It makes sense logically, More air in more air out idea. Been riding for 30 + years not looking to make the bike too loud, as I am off road a bit and don't want to piss anyone off anymore. Thanks..

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Sounds like a hard and expensive way to avoid a simple inexpensive jetting change.

 

There is no filter change you should consider.  Stay with foam.  They are all the same.

 

Q4 doubt will change the jetting enough to notice a difference.  I didn't.

 

For a quick check, how does it run if you take the air box cover off?  Just remove the rubber insert without cutting the air box?

 

Stock main jet is 142.  Easy to go to 140, 138, 135........

 

The needle has a number of shims.  they can be rearranged or exchanged for small washers to lower (lean out) the needle.

 

I would try some quick airbox changes then try a 135 min jet.  See what that does for you

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Thanks for your advice.. Sounds like you have done a fair share of DRZ jetting before.  I have done some jetting, dropping/raising needles over the years, was thinking I could take the easy way.. Guess that mechanic was blowing some smoke my way or maybe wanting to sell me a can... 

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You should reconsider the 3x3.  The bike wants it at any altitude and it's moving the A/F in the right direction for your case at 5000'.  That may be all you need to do.  Someone should have the recommended jet for stock Mikuni with 3x3 at 5000'.

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That's a good suggestion. How do I go about getting the main jet recommendation for 5000 ft with a 3X3 and everything else stock. Do I need to raise the clip or lower the needle or keep it stock... thanks 

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Stock needle does not have slots for clip adjustment. Would have to use washers to change the needle position.

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Buy the JD jet kit.  It's not free, but it's worth it.

 

Do the 3X3 Mod.  It is free, and it helps, a lot.

 

Watch this video and follow the JD jet kit instructions.

http://www.youtube.com/watch?v=VtKWbs0N5lo

 

Go ride, and be happy.

 

 

+1...That's what I would do...the stock needle profile is not performance orientated...

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Well, I just pulled the rubber snorkel off the top of the airbox, and that seemed to give it a bit more air and sort of throaty intake sound.

 

I really appreciate the tips.  I'll probably do the jet kit and the washers for the needle.

 

Wonder why Suzuki did not go with the slotted clip.. toofer

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Well, I just pulled the rubber snorkel off the top of the airbox, and that seemed to give it a bit more air and sort of throaty intake sound.

 

I really appreciate the tips.  I'll probably do the jet kit and the washers for the needle.

 

Wonder why Suzuki did not go with the slotted clip.. toofer

 

 

Ok ....you pulled the snorkel...so you have an E model with fcr carb...???...Yes..??...

 

PLEASE CONFIRM.....

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No , I have an S model, enduro or as they say these days dual sport..  I took off the the rubber scoop that sits on to of the air box and funnels the air into box. 

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Toofer, I run all the time up to 6,500ft and have a 2003 S model with a Jardine(large and loud) exhaust. My bike also has the 3x3 hole and The DJ jet kit. The only part of the jet kit I used was the needle and the spring. The main jet is a 142.5. The bike runs like jack-the-bear, the needle is the key.

 

If I was you I'd get a decent foam air filter and use the filter skin, which is a heck of a lot easier to clean or throw away than the main air filter. I ride in dust as well....at least until I have had my fill and give the Deezer it's head! Then it's someone else's turn to suck dust.

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This is great. I am often up at 6000-8000 feet so I guess the filter skin is a good thing. I'm going to go for the jet kit and keep the rubber snorkel off. I think the needle will be the best payoff for my bike. Rubber-side-down-toofer 

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BTW, I don't think I get much more dirt in the airbox with the 3x3 hole (on top) than I would if the box was intact, so I wouldn't shy from doing the 3x3 for that reason.

 

You can run the stock jet, PJ and just change the needle. I couldn't ask my bike to run better. I also slipped a 25 PJ in, mostly to smooth the transition from dead idle to part throttle when I'm poking my way through the rocks/creeks. Not sure it helped much, maybe just a little.

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This is great. I am often up at 6000-8000 feet so I guess the filter skin is a good thing. I'm going to go for the jet kit and keep the rubber snorkel off. I think the needle will be the best payoff for my bike. Rubber-side-down-toofer 

 

Get a JD jet kit if your buying one....

List what altitude you mostly ride at and we can advise you on carb set up with this kit....

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Why not try it with the stock pipe (quiet)? The Jardine on my bike has a large diameter header pipe and was installed by the previous owner. I have never heard of anyone else with the same system. It's quite LOUD!! I was going to replace the stock muffler section, but kinda like being able to warn the bears that I'm comin down the trail. Only the truly deaf wouldn't hear me coming!!

 

Most DRZ folks recommend the MRD pipe, which is also very very loud.

Edited by shuswap1

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Cool. Should I leave the stock pipe on? If I putting more air in shouldn't I get more exhaust out?

 

 

Of course running a performance carb with a Non performance pipe will restrict your gains.....

 the trade off for quiet is less performance....that's how it works on a DRZ engine....

personally I would be ditching the stock pipe, but it's your call on the noise level which would be acceptable for you and your neighbours etc..  :)

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I have an S with a full Yosh and a 3X3 and am running a 130 main at 3500-6000ft and it works pretty well.  At that elevation, no matter what you do, a re-jet is required for perfection.

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