DRZ 400 carb issues

2009 DRZ 400 with 434 BB Stg 1 hotcams 3X3, dyno jet kit and stock exhaust. when you cruise and then suddenly mash the throttle it kind of stumbles and then takes off and it will barely idle when cold choke or not and if you come to a stop light and go to take off sometime it will just die and it is hard starting after this happens. Jetting is 155 with the needle in the 3rd slot please help!

which dynojet kit is it?

Its a Stg 1&2 Dyno Jet kit for a 05-08 LTZ 400. Figured they were pretty much the same Carb and they didnt offer a kit for a 09 DRZ 400 where i bought it from. It is currently set up to the stg 2 spec just like it says in the booklet thing you get with the kit.

can someone please help? sounds like a fuel problem when you jam the gas WFO its stumbles then catches itself a couple seconds later. I am not familiar with these carbs so i dont know where to start

has 155 jet stock pilot jet 3rd slot on the DJ needle and i belive 3 turns out on the fuel screw anyone have any input?

um...just bought an '05 DRZ 400...1400 miles...idle seems to stick after revving up...usually drops on its own after some time....when coming to a stop will seem to also stick unless if ya come to a chugging stop or after hitting it back to 1st then releasing the clutch a little to simulate a stall and idle returns....last owner said "always been that way"...i noticed some electronic looking plugs on carb (i'm a car technician)...you'd think somethings sticking but I question if it is some sort of "mode" for crawling along a trail so it does'nt stall, (which i've done "chugging at slow speed too far)

um...just bought an '05 DRZ 400...1400 miles...idle seems to stick after revving up...usually drops on its own after some time....when coming to a stop will seem to also stick unless if ya come to a chugging stop or after hitting it back to 1st then releasing the clutch a little to simulate a stall and idle returns....last owner said "always been that way"...i noticed some electronic looking plugs on carb (i'm a car technician)...you'd think somethings sticking but I question if it is some sort of "mode" for crawling along a trail so it does'nt stall, (which i've done "chugging at slow speed too far)

What carby has it got?..What model drz?

um...just bought an '05 DRZ 400...1400 miles...idle seems to stick after revving up...usually drops on its own after some time....when coming to a stop will seem to also stick unless if ya come to a chugging stop or after hitting it back to 1st then releasing the clutch a little to simulate a stall and idle returns....last owner said "always been that way"...i noticed some electronic looking plugs on carb (i'm a car technician)...you'd think somethings sticking but I question if it is some sort of "mode" for crawling along a trail so it does'nt stall, (which i've done "chugging at slow speed too far)

blocked pilot jet

thanx chooken...was figuring it was "BS" put wasn't sure if technology had done something....being this on'es a keeper anyone got any reccomends on a good manual...'course bike came with no owners or shop manual....clymer manuals good enough to go into carb breakdowns??

My Clymer was accurate for the carb breakdown.....

Idle to high? maybe

Eddie just answered this same question a few days ago so I'll pass on the answer. LTZ jet kit is the wrong kit. Not the same carb as DRZ.

thanx...been awhile for me, clymers' always been out there...gonna get one soon!

My question is this. Why did you stick with the stock exhaust? Since you need to rejet get a yosh and jet accordingly. that stocker is holding those mods back.

I am all for an aftermarket exhaust but tbh its my dads bike even though i ride it a fair bit and he has heard the Yosh offroad exhaust on my LTZ 400 and it i incredibly LOUD and refuses to allow me to get any sort of performance exhaust thats any louder than h is drilled out stock exhaust and he saw the dyno sheet on yoshis web site claiming 1 hp on a stock bike with a jet kit but i think he will gain more than that with the mods he has.

ok...got my clymer...great internal carb views but no explanation of how electronic dash trip meters work or how to set them up.....gonna take apart carb next weekend, anyone got any info resources (owners manual type info) on it's capabilities and operations??

hey measlymike!!!! cleaned out the carb...didn't find much cept for some crust around the pilot jet o-ring from old fuel... fired it up and revved a few times and it hung up... ironically turned down the idle screw knob (before i read ur note)but couldn't road test it...just ran it this past friday night and low and behold it's fixed!! gonna caulk off the the carb R&R to a lesson in getting to know the bike to save embarrassment, can't really understand why it would idle lower randomly but either way looks like i shoulda did that 1st!!! at least i got a reason to purchase my clymers...thanx one and all for the coaching!!

A stumble under acceleration is usually too much fuel, causing the engine to bog until it can clear itself and accelerate...

Try a smaller main jet....

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