Jump to content
Sign in to follow this  

Dynojet stage 1 jetting kit question

Recommended Posts

We have a 2001 drz400s model. I was wondering if this kit is the way to go to upgrade our stock drz? According to what I read the needle that it comes with makes good improvements over stock? It says to put in a 25 pilot and a 140 main with the new needle in the 4th clip position.

My question is why would it call for a smaller main jet? Does the new needle make it that much richer?

I want to keep the rest of the bike stock except for the 3x3 mod to the airbox. Maybe drill out the exhaust but most likely not.

Any suggestions on the setup for this bike? Thanks for any help!

I read that this will make the S model go from around 35hp to about 37hp?

Share this post


Link to post
Share on other sites

DJ Main Jets are rated differently to Mikuni...Yes it can be confusing..

Dynojet numbers are simply the hole diameter. A 140DJ main has a 1.40mm (0.055") diameter hole in it at the threaded end.

A mikuni 140 jet has a 140 cc's of fuel flow per minute..

If you haven't purchased yet, I would recommend the James Dean kit....It gives you hex head bowl screws..

BTW..DJ stage 1 is for unmodified air boxes

Edited by craigodrz400sm

Share this post


Link to post
Share on other sites

DJ Main Jets are rated differently to Mikuni...Yes it can be confusing..

Dynojet numbers are simply the hole diameter. A 140DJ main has a 1.40mm (0.055") diameter hole in it at the threaded end.

A mikuni 140 jet has a 140 cc's of fuel flow per minute..

If you haven't purchased yet, I would recommend the James Dean kit....It gives you hex head bowl screws..

BTW..DJ stage 1 is for unmodified air boxes

Where can the james dean kit be purchased at? I was also planning on 3x3ing my airbox soon and leaving my exhaust stock.

Share this post


Link to post
Share on other sites

BTW..DJ stage 1 is for unmodified air boxes

So since I installed a Dyno Jet Stage 1, because that's all that DJ shows on their site for an S, is there anything I can do to make it work better with the 3x3 mod? Move the clip up one notch on the needle, run a larger main jet? I suppose the James Dean kit or even the DJ stage 2, which they aim at the SM, would have been better. But I purchased the DJ kit before hearing about the James Dean kits, or reading about the 3x3 mod. The PO did the 3x3 mod, but never rejetted.

I have the 3x3 mod, full FMF exhaust, and a K&N Air filter.

Share this post


Link to post
Share on other sites

Move the clip up one notch on the needle, run a larger main jet?

Sorry, should have said move the clip down one notch. Correct?

Share this post


Link to post
Share on other sites

So what is the best kit to get for the S model with a 3x3 mod and stock exhaust??? I know the new needle is the main thing, but what should the jetting be also?

Share this post


Link to post
Share on other sites

JD Jeting kit is the prefered kit for all applicatioins. The DynoJet kit will work with modifiedd air box. I'm running a donated S carb with the DynoJet kit, 142 Mikuni main jet, 25 pilot with an E air box. Works fine.

The JD kit assumes the air box will be modified. The DJ kit is silent on the subject.

Share this post


Link to post
Share on other sites

JD Jeting kit is the prefered kit for all applicatioins. The DynoJet kit will work with modifiedd air box. I'm running a donated S carb with the DynoJet kit, 142 Mikuni main jet, 25 pilot with an E air box. Works fine.

The JD kit assumes the air box will be modified. The DJ kit is silent on the subject.

Are there different stages of the JD jetting kit?

Share this post


Link to post
Share on other sites

So since I installed a Dyno Jet Stage 1, because that's all that DJ shows on their site for an S, is there anything I can do to make it work better with the 3x3 mod? Move the clip up one notch on the needle, run a larger main jet? I suppose the James Dean kit or even the DJ stage 2, which they aim at the SM, would have been better. But I purchased the DJ kit before hearing about the James Dean kits, or reading about the 3x3 mod. The PO did the 3x3 mod, but never rejetted.

I have the 3x3 mod, full FMF exhaust, and a K&N Air filter.

So you have installed the kit...How does it run?

Share this post


Link to post
Share on other sites

So you have installed the kit...How does it run?

It seems fine. I have some decel pop. But little, to no, low speed surging. I checked the plug. The tip was white-ish, but the base of the threads was black-ish. Not sure how to interpret that. Maybe I could benefit in the top end from a bigger main jet. Guess I'll have to give it a shot. The DJ kit came with another larger main, and then I was told the stock main jet is bitter yet. There's only one way to know for sure. Too bad it's requires so much effort to get at that carb.

Share this post


Link to post
Share on other sites

What clip is needle set on? and what main jet is installed

I followed the instructions exactly. 4th clip from the top on the new needle. The 134 main, stock pilot because the DJ kit doesn't include a new one, and 3.5 turns out on the a/f mixture screw.

Share this post


Link to post
Share on other sites

Surging can also be down to an air leak on the manifold, make sure all your carb clamps are tight

and it's definitely seated correctly.

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:

Sign in to follow this  

×
×
  • Create New...