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Carb Noob ?Lean?

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have a 2001 DRZ 400s- seized the tranny at 8000 miles and swapped in a 2006 400s(m) motor with 500 miles on it- not sure if it was a SM or S if that makes a difference in this question.

Bike has a full muzzy pipe and header and open airbox and the same 2001 drz400s carb previously jetted by first owner.

Previous to motor swap I consider bike to be jetted perfect. Now it's sounding/acting like it's running lean- heavy duty popping on deceleration or throttle cut.

it is Dynojeted and inside the Jet Kit box - every one of the listed included Main Jets 128, 130, 132, 134, 136 are still in their bags. But there is a old looking mainjet sitting alone that looks like it says 125 on it and an old needle with a clip on it- no adjustment slots. As well as a fuel needle with 22.5 on the side

Instructions for stock pipe use MJ 130 and for slip-on pipe use MJ 134 and this bike had full header - so maybe he used higher than MJ 136?

It says to put the e-clip on groove #4 from the top of the needle.

Assuming you think it's running lean too, do I need to have a bigger number Mainjet than is in there now?

Do I need to take the carb off and out to check and change Mainjet? Is there simple adjustment I can make to add fuel - like turning out the fuel mixture screw?

What possible reasons for running lean with this tight new motor? Only electrical component that changed was 2001 rectifier to 2006 and that ?coil? connected to spark plug wire.

I'm riding at 3000 asl and would go as high as 7000asl this summer

Thanks for input

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you answered your own questions, you need to take off the carb, see what you have in it, if its lean you need to change main jet and needle position, fuels screw only effects just off idle..there are recomendations for the dj kit with your exhaust. 150 main i think, with clip second down on needle, but don't quote me.. i only know jd off the top of my head,, a search will pull up the dj recomendations.

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I went on DynoJet site and looked at instructions for the newer 400SM it uses the 2nd clip and bigger jets, but 400s has same instructions for all years - so then I wonder if it's more of a change in carb for the newer SM's or is it the same carb and motor just needs more fuel?

Here's a noob comment- on the left side of carb I turned the white plastic knob(not sure what it is- do you know :thumbsup: on a rubber flexible tube under the carb a few turns and the majority of the popping is gone on deceleration- honestly thought I turned it clockwise or was it the other way- whoops it worked and I assume turning it more in the same direction will get it right. I then assume it was only lean in the bottom 1/4.

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oooh man,,that white nob is for idle only,has nothing to do with any other carb function! it should be set where it idles smoothly, not fast, just to the point of smoothnes.

as for the carbs and engine are the same on s and sm. I beleive The S instructions were written without the 3x3 in mind, SM instructions written for 3x3 hole(reason for bigger jets), which should be done. So if you havent researched 3x3, do so now, easy to do and should be done. So cut the 3x3 hole, put that jets and needle as described for sm with 3x3. Your obviously new to motorcycles so Keep reading and learning Read all of the FAQ at the top.Your journey begins.Good luck.

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oooh man,,that white nob is for idle only,has nothing to do with any other carb function! it should be set where it idles smoothly, not fast, just to the point of smoothnes.

as for the carbs and engine are the same on s and sm. I beleive The S instructions were written without the 3x3 in mind, SM instructions written for 3x3 hole(reason for bigger jets), which should be done. So if you havent researched 3x3, do so now, easy to do and should be done. So cut the 3x3 hole, put that jets and needle as described for sm with 3x3. Your obviously new to motorcycles so Keep reading and learning Read all of the FAQ at the top.Your journey begins.Good luck.

white nob will not fix a lean condition, has nothing to do with mixture..it adjusts the throttle resting position.. it should turn, clockwise to idle up, counter clock wise to idle down.

My 400s directions are exactly the same as the ones on www.dynojet.com

I have the 3x3 and full Muzzy and it ran great before the motor swap.

The white idle knock did not raise the idle significantly , motor is not racing but backfiring is mostly gone- first I'll try the easier idle adjustment and if that doesn't get it 100% then I'll check setting of Fuel Mixture Screw and enrichen a little.

The white idle knob did almost solve my backfiring- what can it hurt if I'm not setting idle to ridiculous.

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Your obviously new to motorcycles so Keep reading and learning Read all of the FAQ at the top.Your journey begins.Good luck.

Let's say that carbs and electrical are what I'm new to- never had to mess with either on my previous 4 bikes.

I've owned 5 bikes since I started riding in summer 2007. This DRZ was my second bike purchased in 2007. I broke the simple stuff and replaced, but when the tranny seized in 2009 I swapped the motor and left the bike in the corner of the garage for a few years as I got hooked on KTM when I bought my 525exc.

I had the KTM 525 exc and put 75 hours on that, the 640adventure and 2009 530 exc that I put 85 hours on.

I got to know the workings of KTM quite well and then over time changed bikes owning as many as 3 at one time and now all the KTMs are gone and the DRZ comes out of retirement with a 500 mile motor that should be running the same as the last motor that seized I figure- Why would it need to be rejetted or have the carb taken off as it was perfect the years I rode it.

If I get a decent dollar for this fun DRZ it's gone too- not exciting enough for me and I love the KTM 6th gear and 250lbs - nice.

I have my eye on Husaberg 570 fuel injected and the Husa FE650- sure would love to have a 525 exc again as well.

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yah ... i bought a new husaberg .. light ..looked good ...quick motor

along comes the FIRST oil change .. remove drain plug and nearly pass out due to part of the counter balancer connected to the drain plug magnet

concerned ... you betcha !!!

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Between 2007 and 2011 I owned KTM 2006 525exc, 2006 640 adventure and 2009 530exc- made sure I did not buy any first year models(big problems when 2008 530 first came out) and I bought bikes already done up and running great. Zero mechanical breakdowns for all 3 - did have issues with brakes when I did not keep up on replacing pads, adjustments or wrong brake fluid- my fault. Otherwise awesome experience.

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Got a good ride on the DRZ tonight- the jetting is not perfect.

Is there anyway to tell what motor S or SM I have from the serial number ?

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just buy the jd jet kit jds005, and rejet it and cut the 3x3 if you havent,this will end all your concerns and give you proper jetting,and be done with it, then you can ride more and contimplate less..my 2 cents

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From what Eddie is telling me, I already have the proper jet kit installed for my Muzzy pipe and 3x3 as well.

Why reinstall another brand of jet kit when this one was working excellent?

I was trying to figure out what changed when I changed the motor. Apparently not the motor and definitely not the carb.

What's it doing? Runs perfect at idle and all smooth accelerations and on snap throttle drops it has no backfiring- very nice.

On a super steep dry dirt hill it accelerates and acts perfect like it used to - no issues. Same kind of hill but rutted and muddy and the bike loses it's steam - it doesn't continue to act powerful as it used to.

Once in a while on cracking the throttle it bogs and hesitates and than catches and lurches to accelerating.

Trouble shooting ideas?

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there is no difference in S/SM motors. they are the same.

Thanks Eddie, from what you are saying I have the same motor - but now it is fresh with 540 miles. The dynojetting ran perfect from 4200 miles on the bike to 7800. Then it sat over a year and now it doesn't run as well.

Should I consider cleaning the carb and components and how should I do that.

Do you see any reason to swap everything out to a different jet kit when this one was perfect?

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thought i read you had the dynojet kit in it..

pilot jet=idle to 1/4 throttle

Needle=1/4 to 3/4

main jet=1/2 to wot.

just incase you didnt know the carb jet order,, might help you diagnose since you said bogs on cracking throttle..weel good luck,,i would say a carb cleaning would give a clean base to start with,,thats about all i can help you with, i think your on a mission...later

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then it sat over a year and now it doesn't run as well.

Should I consider cleaning the carb and components and how should I do that.

if you have done the 3x3 mod you really dont have the correct kit. it can be made to work.

your issue is likely due to the carb sitting for a year.

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if you have done the 3x3 mod you really dont have the correct kit. it can be made to work.

your issue is likely due to the carb sitting for a year.

OHhhhh- not the correct jet kit- interesting. I don't see a Dynojet kit that covers full pipe and 3X3 for the 400S- I see a Stage 2 one for the E.

I have the Stage 1 kit #3109

http://www.dynojet.com/jetkits/motorcycle/suzuki.aspx#250

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