[Z400Gramps]

This is a further update on fine tuning my set up which consists of the CFM Open Top aluminum airbox, K&N Filter with water repellant Outerwear and jetting with the Dyno Jet Stage 1+2 kit. Everything else on my Z is Stock including the muffler!

When I installed the airbox I found that you have to remove the screen disk from the intake runner where it joins the airbox, everything else is simply removing the old and installing the new.

I started the jetting at the reccomendation of CFM which also corresponds with the Dyno Jet Kit, 146 main, needle clip in the 3rd slot from the top, 3 1/2 turns out on the air screw. This set up seemed to run real well and I was impressed but I was concerned with what seemed like a flat spot on the top end. Much like what has been described in other threads as whether it was the rev limiter or a jetting issue. So I spent most of yesterday trying different jets and needle positions to no avail! I thought by the time that I got done that I was going to have to buy a pipe!

A stroke of brilliance! READ THE DIRECTIONS THAT CAME WITH THE JET KIT!
I have said before that these companies spend a lot of money and time developing these kits and are far smarter than I when it comes down to what works yet failed to heed my own advice! I am below the 3000 ft. elevation and the 146 main jet is what they reccomended but going thru the directions I came upon the portion that dealt with what I was experiencing. Real simple, get some duct tape and start closing off the amount of air getting into the airbox, if it starts to rev better and more consistant then you are to LEAN! If it gets worse then you are to RICH!

As I started closing off the airbox my Z started to rev without hitting the flat spot that was present which meant that once more I would have to change the main jet. Since I had closed off all but a 1X3 inch area I went straight for the largest jet provided. I installed the Dyno Jet 155 main jet and left the needle where it was. Put her back together and WHAT A SOUND! No flat or droning at the top, she now revs!

 

[Steve-O]

Hey gramps
are you using the stock spacers on the needle still? if its not in there there's alot of side to side play
Im asking because i have nearly the same setup stock air box though w/ l the lid off and snorkle removed. I have the alba jet kit and there was no instuctions with it. Currnetly running a 150 main 25 pilot and 3 turns out on the mixture screw.clip 3rd from the bottom with the white nylon spacer under neath?!?! again not sure if it supposed to be there.

basically its idleing good but when i gas it it dies out. when I leave the choke on it revs fine.

Your right about the sound nice mellow rumble now. amazing

 

[Z400Gramps]

There is actually 2 washers, 1 steel and 1 nylon that go under the clip and 1 thin one that goes on top of the clip and then the small spring and the gray plug seated firmly.

The clip should be in the 3rd slot from the top of the needle which I presume is the same as the 3rd from the bottom but jet kits refer to it from the top.

Sounds like you don't have something quite right if it won't take full throttle without the choke on. Try doing what I mentioned in my post and see if that cleans it up for you. As I stated in my post the only jet that I changed was the main.

Let us know how you make out!

 

[Steve-O]

I know what was happening now.I tried installing the cap and needle at the same time. and the needle wasnt going into the main jet. causing the plastic plug to pop off.

right now i have it set on the 3rd from the top. without any spacers especially that nylon one. judging from the size of it looks like its equal to two or three slots on the needle. wouldn't running that under the clip raise the needle that much more and cause a rich condition?

I havent riden it yet but the throttle feels very responsive as it is. Only some saddle time will tell for sure. just a lil fine tuning one the air mixture and i think im set.

btw a guideline i found for the air mixture/main jet setting: anything more then 4 turns out you need to go up to the next larger main jet.

 

[Z400Gramps]

Not to be smart but are you stubern? The way I described it to you is the way it goes! Now take it apart again and do it the way that I described! LOL! You didn't mention what filter you are using and if you have the stock filter in there you may have to large a main jet installed. I will continue to help anyone as much as I can but when they don't want to listen then I stop helping. I am not trying to be harsh but I think that I was quite specific in my first post. 8O

 

[Steve-O]

all set now
It wasnt because I following your guide lines i already tried different settings before i posted and at that time . some sort of instructions with the kit would of helped out,, urghh alba :?

and there was no mention about the white nylon spacer in your first post,, just for the record
Thx again and it is a nice boost in power btw.. still getting used to the sound. surprised how much louder it got.

 

[Z400Gramps]

Sorry, you are right I didn't mention it in this post. Senior Moment! :? I know I talked about it in one of the threads though, good thing my brain is encapsulated or I might forget to bring it along from time to time! LOL!

Glad to hear that you have it figured out and hope you have fun!

 

[JeffP]

Ok gramps I'm going on your recommendation and installing the 155 main jet. I also have the CFM box with a Uni filter (drilled out exhaust tip) and my elevation is about 6ft above sea level. I sure hope your right as getting in there to change them out woln't be on my priority list.

Thanks for the tip, hopefully it applies to me as well.

-Jeff

 

[Treystoys]

guys...I'm pretty sure the nylon washer in the kit is for half a clip space on the needle...I don't recall off hand, maybe someone else can back me up here.