Jump to content

Where to start for MY jetting

Recommended Posts

Ok, so, this is my carb thread. I am mechanically inclimed, but have no idea how to work on motorcycles. I weigh about 270 lbs with a backpack. I have a 14t front sprocket, and a 44t rear sprocket with a 520 chain. I ride almost all street. Currently on D606 tires. But will be getting a more street friendly tire soon. I do have a 3x3 airbox mod, and a full yoshi rs3 exhaust. Temps around here are between 30*f and 105*f. There may be a little more or less, but little deviation to that if any. I am at sea level for the most part. I will be dirt riding, but seldom. Where should I start for my jetting on my 2005 drz400s? I know there is no magic number, but if I correctly recall what the po said, it has stock jets on it. He had a carb kit, either moose or dynojet from what I see, but said it performed better with the oe jets. I am not so sure. I want to maximize my power if possible. Also, I run premium gas if it matters? And have a clarke tank

Share this post


Link to post
Share on other sites

Get a JD jet kit and follow instructions, or buy your jets and needle individually. Check out this spreadsheet, there are people with similar mods and climate as you. https://docs.google.com/spreadsheets/d/1HNSB3DrqJqHTInjVDKKS4HNSHZPbdK0ElbfNI5HxuZg/edit?hl=en#gid=1172546203

Personally I believe running higher octane than the manual specifies is a waste of money (unless required by other mods like increasing compression), and the Clarke tank makes no difference.

  • Like 1

Share this post


Link to post
Share on other sites

just get a jd jet kit ... it will tell you where to start .. and typical pump premium is the only thing thats adequate imo in anything over 9:1, regular is for lawnmowers, grocery-getter cars and things like that ..

Edited by cowpie
  • Like 1

Share this post


Link to post
Share on other sites

For the cost of gas in the bike, premium is fine. As for the notingthe clarke tank, the extra capacity is added weight. I already have either a moose or dynojet kit. Most of the needles are still in individually sealed bags.

Share this post


Link to post
Share on other sites

Ok, so a couple questions, how can I confirm I have a CA bike? I saw some youtube videos, and I don't have a vacuum line? Or it is plugged? Also, in a video I saw, there was another electrical connector that wasn't the tps, it was lower down. I don't have that.

Here is where I am at. My kit is a Dynojet, that is sold by Moose racing. It also says for a 2000-2004, but my DRZ is a 2005... would that matter?20170617_001524.jpg20170617_001353.jpg20170617_001329.jpg20170617_001259.jpg

Share this post


Link to post
Share on other sites

Hi 74jimbo,

I have a very similar set up to yours; 3x3 mod, Yosh exhaust and JD jetting kit and I ride mostly at sea level in temps that can go to 100 (but usually don't ride when it's this hot).
....I say "mostly at sea level"  but also occasionally ride from 6000'-9300' when I do my mountain trips.

Here's what I did that has worked fantastically well.
I got the JD jet kit and set it up as per the instructions for sea level, 3x3 mod and what they refer to as "a more free flowing exhaust" and used
the BLUE needle with the clip in the 3rd grove from the top (#3), #160 main jet and #25 pilot jet.
Set up like this, my bike runs great!

I figured the above set up would be good for my mostly sea level riding and that I'd have to rejet for my high altitude (6000'-9300') riding.

However because I'm lazy and hate fooling with carbs, when I went on my high altitude trips I did .....nothing to the carb except turning the fuel mixture screw in from the JD recommended 2 1/2 to about 1 1/2.
And to my surprise the bike runs great at high altitudes also.  Starts easily, runs strong and has plenty of power.  --I'm 220 and usually carry 15 pounds of gear on a rear rack.
While JD does recommend smaller jets for higher altitudes I've found the set up as above runs plenty good for me.  --No doubt I'm running a bit rich at altitude but it seems to work well.  Or well enough for me.
So the upshot here is I'd say set it up as above and just leave it alone and enjoy it.

Share this post


Link to post
Share on other sites

Well, I totally necroposted an old thread, and I am satisfied with the info I have received. I have come to realize, I have a franken basket of parts, and my next step is to buy the JD kit and start fresh when I get some extra funds..

The experience was good though. I could probably do it in like half an hour now, just knowing how. I took out the dynojet 138 and put in a stock 142.5.

Dynojet has weird crossover numbers, and my mass of random jets isn't helping the situatuation

  • Like 1

Share this post


Link to post
Share on other sites

the dynojet kit was not developed for the 3x3 mod and has never been updated.the stock 142.5 main jet should be correct for that kit (3109) as well as the stock 22.5 pilot jet for high altitudes.the mikuni is pretty tolerant of altitude changes.

Share this post


Link to post
Share on other sites

ok, soon, I will be getting the JD kit. JDS005

do I need anything else while I am at it?

should I get a 22.5 pilot? or 25 pilot?

also, saw another thread here that talked about the mixture screw.. mine may or may not be stock? I thought stock there was a plug? I do have a screw, but have no idea about it. It has a D shaped head if that matters.

I do have the 3x3 and Yosh RS3 full exhuast

Share this post


Link to post
Share on other sites

got my jd kit today. a couple of things..... so I have the kientech screw already. also the jd kit came with a 25 pilot jet and says to run the 3rd spot on the clip. I thought everywhere on here said to run the 4th?

I also noticed it says to run the fuel screw to 2 turns out, but I have the kientech, where should I put it?

I do have a 22.5 pilot on order and will be in on wednesday....

I will be runnign the blue needle with my setup.

to start, I want to be very ballpark, I will have a friend of mine (he knows bikes, but doesn't have a DRZ) who will assist me in doing the final tuning

Share this post


Link to post
Share on other sites

The instructions in the jd kit are very good and following them should give you a good base line,every bike is a little different.You may or may not need the stock 22.5 pilot jet depending on which fuel screw used and riding altitude.

Share this post


Link to post
Share on other sites

I ride at sea level, sf bay area, ca. I have the keintech screw

Share this post


Link to post
Share on other sites

You'll probably have better luck with the 25 pilot but every bike is a little different.You;ll need to start testing with the motor hot,at full operating temp,slow the idle down temporarily and test the idle's reaction to the fuel screw and set it for smoothest steady idle.If more than 3 turns or so a larger pilot may be needed or if closed off it may need a smaller pilot.Start at the base line and go from there.

  • Like 1

Share this post


Link to post
Share on other sites

I have a same bike, just 2004 year.

My JD kit is on the way ;). PDF manual JD says blue clip 3rd but some guys are running clip on the 4th position.

Main on 160, 25 pilot jet - with open exhaust and hilfo air filter (3x3 mode)

JDS005.jpg

JDS005..jpg

Share this post


Link to post
Share on other sites

what is the other jet supposed to be? not the main jet in the picture, and not the pilot.

 

also, what jetting should I use considering I have the 3x3 mod and a yoshi rs3 offroad exhaust?

Share this post


Link to post
Share on other sites

So I got it running. Still not right. But it runs.... 155 main, JD jet kit, blue needle, 3rd from top. 25 pilot, 62.5 air jet. Also, does the throttle snap back closed by itself? Mine doesn't. Check it out. Keintech screw about 2 turns out

 

 

 

 

 

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×