DR-Z Kickstart-only model 01 - what jetting for better hot starts?

Hello :thumbsup:

I recently had my mechanic re-jet and readjust my carb according to Eddie's specifications found in this thread

148 main jet

5th clip

48 pilot jet

2.5 turns fuel screw

However the bike seems weaker in the low end, stalls more often, and kickstarting when hot became very difficult. For cold start, I dont need choke, but when coolant temperature reaches 60°C (140°F) and more, it is impossible to start it without using hot start button.

Either my mechanic screwed up something, or I need leaner idle circuit.

So what would you suggest? I guess tampering with needle and fuel screw is not enoucgh. The priority is hot starts, I dont care if cold starts will be worse.

that is what the hot start button is meant for

iowaBClivewire> I dont belive so. It is meant for crisis situations, like after flipping the bike or when really hot (almost boiling). 60°C isnt really a hot start.

You see, the choke button which serves as help for cold starts, is now totally redundant, while hotstart button is necessity. You see what i mean?

than wate for the reply of the masters

ok, anyone? :thumbsup:

My DRZ400E '02 with old style FCR

160 main jet (stock is 165 in EU, 155 runs fine too and it's better for higher altitudes)

5th clip

45 pilot jet

2 turns fuel screw

Also as per Eddie instructions


Anyway, the problem you have is on the pilot circuit, try this

48 pilot jet

1 1/2 turns fuel screw


45 pilot jet

2 turns fuel screw

have fun,


Eddies jetting are typically spot on but not always. Bikes are different from time to time and other variables can affect the numbers. So it is a good idea to always confirm through testing they are right for you. It certainly seems like you have a way rich pilot/fuel screw setting.

Fuel Screw/Pilot Jet Setup

Fuel screw settings in the 'book' are recommended starting points. Every bike is different, as is the temp and altitude. Set the screw according to this method.

Gently turn the screw all the way in. Now back it out two turns. Start the bike and fully warm it up, go for a 10 minute ride. Set the idle to speed to 1,500~1,800 RPM as best you can (I know, without a tach this is tough, just set it to were it idles relatively smoothly). Once warmed, slow the idle to the lowest possible speed.

*** When turning the fuel screw, keep an accurate 'count' of the amount you are turning it and record it in case you have to reset it for some reason. Makes life easier when you can just set it from notes Vs. going through the procedure again.***

Turn the screw in until the idle becomes rough or the bike stalls.

if it stalled, open the screw about 1/4 more turn. Restart it and slowly screw it in till you can just perceive a change.

If the screw can be turned all the way in and the bike still idles perfectly and does not stall, then you need to go down a size in pilot jet.

Now very slowly, open the fuel screw till the idle is smooth. Blip the throttle, let the bike return to an idle, wait say ten seconds. Confirm it is the same smooth idle.

If the screw has to be opened more than 3 turns to get a smooth idle, you need to go up a size in pilot jet.

If you find it does not stall with the larger jet but has to be open more than three turns with the smaller pilot jet, put the larger one in and set the fuel screw at 1/2 turn.

If the idle speed increased, adjust the idle speed knob to return the bike to a real slow idle speed. You must then re-visit the fuel screw. Keep doing this till the fuel screw is opened just enough to provide a nice steady idle at the lowest possible RPM. Once this is done, increase the idle speed to the normal one for your bike, typically about 1,800 rpm, but go by the spec in your manual.

The hot start is not just for crashes or tip overs. Any time the bike is hard to start when hot, you use it.

all of my fuel screw suggestions are a starting point with a stock or known good fuel screw.

doesnt matter what setting it is you need to optimize the pilto circuit with the proper fuel screw tests.

are you riding at 6000ft where you are at?

jiauka> thanks, Ill try some of that configs, maybe it will work. Its good reference :thumbsup:

William1 > this is very helpful and well described, thank you! I have rpm counter installed on my bike, so changing idle as you described will be easy. Currently I have 1100+ and that is total minimum. Ill get to work on the weekend!

Eddie Sisneros> My fuel screw is definitely stock, if thats what you're asking?

doesnt matter what setting it is you need to optimize the pilto circuit with the proper fuel screw tests.

-does that mean my problem can be solved only by setting up fuel screw? (Assuming there is nothing else wrong within the carburetor itself) I thought that it is only for fine tuning?

My altitude is mostly around 1000 ft :thumbsup:

the setting you are using is for 6000ft.the main jet is too small.

what pipe are you using?

oh. What about if I tried 158? Also have 160, 165 (that one was stock, spark plug was all black so I guess it was too rich)

I use stock european E pipe, which was waaay too loud for enduro riding so I modified it to be quieter, I guess you can consider it stock US version E pipe.

And I run standard oiled foam filters.

Thanks for that main jet recomendation, however, should I meanwhile order smaller pilot jet or can that hotstart issue be solved only by fuel screw and needle positioning?

158 main jet,turn the fuel screw to 1.5 turns.

Will try! Thank you very much, Ill report back after weekend :thumbsup:

Wooow, that fuel-screw-thingy is magic :ride:

Now it starts easier than a moped. I warmed it as much I could on this cold summer day (90°C) and bang, one vague kick and we go :p

So thanks again very much, jiauka, William and Burned, I didnt think this would be THAT easy, this is one of those "why didnt I do it before??" cases


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