DIY Re-jet and 3x3 Thread

[cmg1558]

DIY Re-jet and 3x3 Thread: - PDF Verson Here

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Reason for Write-up:

I write this months after I have done my mod, so please PM me if any info is incorrect. I am compiling it from the notes I took awhile ago, so please forgive me if I do not credit those of you that I got the info from, much thanks to those. Another reason I am taking the time is that I would like to have a complete article that answers the most common questions and relieve Eddie from weekly questions of jetting recommending questions. If I don’t list your jetting specs, please let me know and I will try keep this updated for a while.

Intro:

This mod opens the air box to let more air (3x3) and with more air, you need more fuel (re-jet), which can be compared to sucking through a coffee stirring straw, then switching to a jumbo straw. The low down on the re-jetting. Each bike is shipped to the US setup exactly the same in a large metal reinforce wooden crate. The dealership then unpacks it and puts it together. They are responsible for re-jetting the bike for the altitude it will be sold in. DO YOU TRUST YOUR DEARLERSHIP? I am sure most set it up right, but one size off on the main jet or the air jet can make a big difference in power and/or responsiveness. This is why your bike may need to be rejetted. Also, the kits come with a new needle which I hear to be the big key in the whole deal. It has a special taper that the stock needle can’t perform to. Lastly, if you cut the 3 inch by 3 inch square hole in the top of the air box, the carb does not have to suck as hard and allows a larger volume of air which leans the mixture out. You need to add more fuel to the mixture to correct it with the re-jet. [?Eddie - am I using Lean/Rich in the correct way]

Warranty:

If your bike is new and has warranty, talk to your shop about cutting a hole in the top of the air box. My dealer said it would void the warranty on the air box only, not the rest of the bike. He also stated that this would never be a problem and encouraged me to do it. He has a DR-Z which he opened up as well.

Carburetors:

There are two different types of carbs that come with a DR-Z 400 depending on your model.

• DR-Z 400E – FCR

• DR-Z 400S – Mikuni

• DR-Z 400SM – Mikuni

The S and SM both share the Mikuni BSR36 carb. The Mikuni carb is a constant velocity carb and is better in the since of EPA. Bad thing about it is not that great with throttle response, even after a re-jet and is why the TT Store offers an FCR replacement - Link. That is why you will find the FCR on the 49 State Legal DR-Z E model, CRFs, and almost all other 4 stroke dirt bikes. I still have the Mikuni and I am very happy with it at the moment. So, if you have the money start off with re-jetting the FCR with the 3x3 mod, if not re-jet the Mikuni, you will be happy you did.

Jetting Kits:

There are two manufactures on the market that sell jetting kits for the SM and S model. This article is geared toward the DJ (Dyno Jet) Jetting Kit. JD (James Dean) Jetting use to only manufacture a kit for the Keihin (FCR) carb which comes on the DR-Z E model. JD now makes a complete kit for the DR-Z S model and the SM. From what I understand, the performance is very close to the same. The difference is that the JD kit has all the parts included in the kit versus the DJ kit which you will need to buy the Main Jet and the Pilot Jet to complete the install. All that you will use out of the DJ kit will be the Needle and Slide Spring. The JD Kit does come with the instructions to do the full 3x3 mod on your DRZ and has some base line jetting specs unlike the DJ Kit. I have seen some users posting ?s on jetting specs for the JD Kit though. Not sure if they are having problems with the JD jetting specs.

• Note: The DJ Jetting Kit has a different kit for the S and the SM which includes slightly different jets, so make sure you get the right kit for your model.

Time:

Tare Down - 30 min

Carb Re-jet - 25 min

Put back together - 30 min

Fine tuning - 15 min

Total - 1 hr 40 min, but allow 2 and half hrs

Tools:

Cutting Hole in air box

- 3" Putty Knife

- Propane torch

Bike

- Metric Sockets

- Metric Wrenches

Carb

- Proper Phillips (must fit nice and tight)

- Screw Driver

- Drill

- Carb Cleaner: Spray

Parts:

Dynojet DRZ S Jetting Kits

- SUZ 00-07 DRZ400 S

Dynojet DRZ SM Jetting Kits

- SUZ 00-07 DRZ400SM

Keintech Fuel Mixture Screw - DRZ S/SM Mikuni Carbs

Why - The final fine-tuning (after 3x3 and jet kit) is done with the fuel mixture screw to get the best off idle throttle response. For some people, 2.5 turns out works, for others 2.75 works. With the extended screw you can reach down and turn it in say 1/4 turn, ride the bike a few miles, turn it again, test, turn it outwards 1/4 turn past your original setting, test, repeat until you find the setting that seems the smoothest running.

Mikuni Jets

#25 PILOT JET MIKUNI

140 SM RD MAIN JET MIKUNI

ThumperTalk Mikuni Float Bowl Bolt Kit

Why – Because the Phillips head on the stock bolts are soft, like butter, and you will end up having to replace them.

JD Jetting Kits - DRZ400/E Keihin

- JDS001 - Suzuki DRZ400E/K (NON-CALIF)

- JDS005 - Suzuki DRZ400S/SM/E (Calif) (00-07)

Twin Air Air Filters

Why - Tuners make sure you use an after market filter with the DJ mod. At first I didn’t and had the notorious off idle bog with the stock air filter!

Do you have to drill out the fuel screw and replace with the extended fuel screw?

You don’t have to get the extended screw, you can live with the stock short one. But you must gain access to the stock screw still by drilling out the cap. You must be able to adjust the fuel screw for fine tuning. Ask your self this question: is $15 worth hassling with sticking a homemade tool up underneath the carb next to the hot engine each time you want to make an adjustment. Just get the KEFS.

Jetting Charts:

• Choose your jets and settings per altitude and temp.

• When comparing the jet size, the DJ Kit will use smaller main jets that the JD kit due to the size of the needle. So be careful when choosing your jets.

• All Jetting Specs are for a 3" by 3" square hole in the top of the air box. Not 3 - 1" holes, not a larger hole, not a smaller hole, not anything else. You will be on your own for your jetting specs. Eddie has tested and found 3x3 to be plenty.

Jetting for Mikuni Carbs and the DJ Jetting Kits

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3X3 and DJ with stock exhaust (MJ, PJ, Clip from top, fuel screw normally starting at 2.5)

140,25,4th, 2.5 sea level-2000

136,25,3rd 1800-3500

134-136,25,3rd over 3000

128,25,3rd 5000

126,25,3rd over 6000

124,25,3rd up to 12000

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Jetting that others here have used with success.

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2000-2007 Suzuki DR-Z400S Specs

Stock Exhaust

128, 22.5, 3rd, KEFS 2, 6,700-12,000, (13mm float level, DJ Spring)

130, 25, 3rd, KEFS 2.5, 3,500-8000, (Uni Filter, Restrictor Removed)

130, 22.5, 3rd, KEFS 2.5, 5,300-8,000

132, 22.5, 3rd, 5,000 – 13,000, (13mm float level, DJ slide spring)

136, 25, 4th, KEFS 2.5, 2,000-6,000, (1 3/8 Restrictor Removed)

140, 25, 4th, KEFS 3, Sea Level/0-100F

140, 25, 4th, KEFS 2.75, 200/50-100F

140, 25, 4th, KEFS 2, 200/80-90F, (1 3/8 Restrictor Removed)

140, 25, 4th, KEFS 2, Sea – 3000/70-95F (No arrestor)

150, 27.5, OEM, KEFS 1.25, Sea-2,000/50-110

Aftermarket Exhaust

138, 22.5, 4th, KEFS 1, Sea – 3,000, (Float Level 13mm)

140, 22.5, 4th, KEFS 3.5, Sea Level, (screen cut out+ Twin Air Filter)

142.5, 25, 4th, KEFS 2.5, 300 -5,000/40-100F (DJ spring)

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The JD Jetting Kit comes with Jetting Specs

The Work:

Short Version:

1. Remove the following: Seat, both Side Panels, both Radiator Shrouds, and Gas Tank
   
2. Cut 3x3 Hole
   
3. Loosen Sub frame and Tilt back (allows air box boot to move back for carb removal)
   
4. Loosen claps that hold the carb to the air box and intake
   
5. Disconnect the throttle cables
   
6. Disconnect the TPS
   
7. Remove carb from bike
   
8. Change out Slide Needle
   
9. Change out the Main Jet and the Air Jet
   
10. Check or Set Float Height
    
11. Remove brass plug for Fuel Screw
    
12. Pre-Adjust Fuel Screw
    
13. Reinstall carb
    
14. Put the bike back together in the reverse order
    
15. Warm bike up and Fine tune
    

Detailed Version:

- See Below or DIY Rejet and 3x3

Fine Tuning:

Burned’s fuel screw setting method:

1. With the bike warm and idling turn the fuel screw in till the idle drops/misses.

2. Then go back out till the idle peaks/smoothes.

3. This should happen between 1 and 3 turns out.

A. If you end up at less than 1 turn you need a smaller pilot jet.

B. If more than 2.5 (or 3 turns on a cv) you need a bigger pilot jet.

4. Choose the appropriate size and retest.

Understanding Throttle Range vs Carb fuel/Air Circuits for Tuning:

Use the following links for understanding what circuit is being used at what throttle position to make adjustments to your carb.

• Links for more info

 http://www.thumperfaq.com/jetting.htm

 http://4strokes.com/tech/carbover.asp

 https://www.thumpertalk.com/forum/showthread.php?t=404426

References:

The Master 3x3 Post

Ivan’s Jet Kit Installation Walkthrough

Goes through rebuilding carb

http://www.cartestsoftware.com/fz1/jetkitinstallation.html

Bayoubikebruiser’s DJ Jet Kit Installation Walkthrough

Goes through the install of a DJ Jet Kit re-jets with TT FMF SM kit (pics)

[cmg1558]

Finally got it done. Posted some of my other walk-throughs on my server.

http://www.goodaleportal.com/index.php?option=com_docman&task=doc_download&gid=8&Itemid=42

Going to work on some others as well. Next to come is replacing Fork Springs and Fork Oil Change. Let me know if there is anything I have missed or am wrong on.

Thanks

[headster]

Thats is one comprehensive write up!!! Well done!?

I have to say that a Impact Driver is something that i couldnt have done my rejet without. As you say they stock float bowl screws are like butter. A few taps of the impact driver and out they come nicely! :confused:

[HighRevz]

So tell me, what are your first impressions of the bike now?

[another drz guy]

Now that's a write-up! Good work!

[bkdR1]

Nice job, very useful information. Thanks

[underthetire]

The 04 and later E model has the same carb as the S model. Just did the S mod, worked great.

[beemerwolf]

thank you kindly cmg :ride: GREAT WRITEUP!!

I've just printed it & will file in my reference notebook for the DRZ400S

Happy Riding !!

[RobbieO]

This one deserves some fuel!

[cmg1558]

Thanks all for your input. It is nice to know that it is helping others out. Love giving back to the TT and DRZ forum. It makes it worth the time. Yes, this mod made a big difference. I did not have the money for the FCR, but some day I hope to upgrade. On a new bike, there was and still is many things to still get. I have most all of the bike protection gear, now I just need some for me. With the weather, I have yet to test out my new fork springs and Jimmy B. bars. Have the DRZ rack on order and am contemplating the lighter flywheel. I do 95% trail. I will try to continue the DIY docs as I do more mods on the bike.

Be safe, and thanks for the fuel. Maybe it will be enough to get started on my next document, Fork Springs Replacement and oil change.

Chad

[tallasatwee]

This would be great if it were made into a sticky so it's easy to find and referance

[RZDRZ]

I have never heard of dealers being responsible for re-jetting a bike. I have only ever seen them come set up from the factory.

[sneyeper]

Did I miss it? Link is not working 8(

[unimog]

Very nice thread! Unfortunately this is not gonna stop us from bothering Eddie

[BUBONICON]

steal my thunder will you

?

i officially bestow on you my master 3x3 post designation

send eddie a pm and ask him to include this thread in the reference sticky.

[archscat]

will the dj kit for the 2006 drz400sm work with the 2006 drz400s ? the sm kit comes with more jets but a different needle. i have a 2 bro's racing slip-on pipe and i will do the 3x3 air box mod.

[codgemiser]

The 04 and later E model has the same carb as the S model. Just did the S mod, worked great.

I thought only CA E models used the Mikuni carb.

[Wayward Son]

and now all 07 E.

[cmg1558]

Did I miss it? Link is not working 8(

I got it fixed. Sorry, not sure what caused the link to change!

[cmg1558]

I have never heard of dealers being responsible for re-jetting a bike. I have only ever seen them come set up from the factory.

I got to see my bike put together. It was shipped from Japan in a wooden crate 90% assembled. There is no way Japan (factory) knows where each bike they build will end up (Sea level / 12,000ft), so they jet them with a standard setting. It is up to the dealership to set it up for the area that the buyer will use it in or the area that the dealership is located in. My dealership did not change it because it is setup for sea level and we are at 900ft, which is close enough, for them. But, I could be wrong. This is what I was told by my dealership.