airbox 2
 

alright guys got my air box today got it on right away wow what a difference all the way up to 4700 to 5000 rpm then i get a bad stutter never had it before. I did a search because i remember seeing a thread about a hick up about them rpms but every one said it was because the air filter being a k&n, to much air but remember i have been with out a top since i owned the bike and no problems like that before the only thing the bike did before with no lid was lacked some on the bottom end like when it was at idle and you cracked the throttle it stumbled about 2000 and up now i got a crisp throttle, any help would be great:confused:

What is your jetting set up?

stock front 175 rear 178 slow 45 im in colorado

alttitude 5280 here in colorado

as far as i know the only mods that would affect jetting are the k&n and a set of d&d pipes

also if i remember right when i cleaned the carbs out they had a clip on the needles this is my first bike so these carbs are new to me i am used to the smaller kehins and mikunis that are on my skis, i guess what i dont understand is the bike runs great except that one dead spot

Sounds like you are dealing with altitude. You might want to try the "High Altitude" settings which is dropping the mains down 1 size, so you would need to pick up a 172 jet.

i would have to assume that is why i ran alright with out the airbox lid or is that wrong

then move the 175 to the rear correct

Yes that is why it ran ok on the top end and also why the bottom end was so bad.


Yes that is the correct set up.

i will pick up a jet tommorow and try that thanks

It shouldn't fall on its face with stock jetting and stock exhaust at 5200 ft.

Mine started getting too fat and stumbling at higher (>7000 RPM) at about 7000 ft, with 2Bros cans and 180-185 jets. It wasn't a problem with stock exhaust. Definitely not a problem at 4500 RPM.

Are you sure about the jet sizes? Have they been drilled out, by the PO to try and get it to run without an airbox?

Also...
That sounds like somewhere around the middle of the slide travel (only a guestimate). That would also be somewhere in the middle of the needles.

You mentioned needles with grooves. Where are the clips located on the needles?

it has d&d exhaust and im not sure about the jets i just took the carbs apart to clean them because the bike sat for three years with out being started by previous owner

that i also am not sure of where should i start with the needles

Somebody correct me if I'm wrong, but IIRC, you will probably want to be in the 3rd or 4th groove, with stock mains. 3rd groove with 180-185 mains. That's just a top of my head starting point.

But the reason I came back...

If the PO put a jet kit in, it has a different spring for controlling slide travel. It requires that the slide bodies have a small hole drilled (at least the Dynojet version does). If he put the springs in and did not drill the slides, the thing will probably dumping fuel in the midrange, because the slides would open too early.

Just another possibility.

ok will check it out tomorrow thanks all the info really helps thanks

how do you tell the diff in the jet kits and were is the hole drilled

That is why I asked what the jetting set up was. If it is not stock (like you said in post #3) then I need to know what you have before I can give any advice.

how do tell what jetting i thought you were talking about jetting size

regardless i will have the carbs apart tomorrow after work and get as much info as i can again thanks for the info

recycle the K and N. Sorry, its a worst purchase and should be known to all.

that is what i kind of understand it was on the bike when i got it i think what i gather from this site is that the oem filter is fine right

Yes the stock filter is the way to go.

Now for the jetting. You will need to remove the needles from the slides (use a diaphragm cover screw and thread it into the needle holder and work it side to side a bit as you pull it out, also be careful as there are washers under the needle and you don't want to lose any)

Then let us know the following:

Do the needles have 5 grooves for a clip (if so what groove-counted from the blunt-is the clip in and how many washers are on each needle) or do they look like a nail with a big head.

How long are the springs for the diaphragms

on the end of the slide that the needle comes out of, how many holes (besides the one the needle goes into) does the slide have

What are the numbers on the main jets and do they have a star by the number

With this info we can get you set up.

Well mine is on the 2nd grove from the top (blunt end) with one washer on the front and two on the rear but I also have HRC needles and #48 pilots so it might be different with the other kits.

thank you 8541hawk i will have the info tomorrow

Also one more thing to check while you are in there. On this bike the emulsion tubes are different on each carb. These are the parts that the main jets screw into.

So to make sure someone didn't mix them up (and to make sure they are clean) pull them out and check them.

Here is how they should go:

Attachment 10986

notice the small holes on the body are in different locations.

I know yours is sorted.

Hopefully this stuff helps people to understand the mysteries of CV carbs.

ok guys picked up a stock filter today what a crock but we will see 56.00 also picked up a 172 main just in case here is the scoop pulled the carbs one washer in front of the clip the needle has 6 grooves the c clip is in number five from the blunt end no washers behind the clip and like i said the jets are as follows 175 up front 178 in the rear and 45 for the slow jet there is a big washer onthe back of part that the needle came out of also all the jets do have stars, what do the stars mean the new 172 has a star in front of it

oh and the spring behind the needle is about 7/16 long also there is to holes on top of the slide and one below so a total of three holes beside the one the needle goes through

also the emulsion tubes are backwards have been that way since i owned the bike so how does that effect the bike

thanks to the know how of every one here they will be back in there right home

ok one more problem to the puzzle after further inspection between the new jets and the old jets they have been drilled i dont know to what so i dont know were to go from here for a new size

So there is one more hole than this pic?

Attachment 10987


Also the spring I was asking about is the long one that comes out when you remove the cap to pull the slide out.

yep one more hole lower left corner the other spring is 5.5 inches long

Well you have part of a DynoJet kit in there. The bad part is this is the kit I like the least and no the least about.

I will have to do a little checking to find out what size mains to recommend.

To answer your other questions, the star on the jet means it is a jet made by Keihin, but as the one you have are drilled out they need to be replaced.

The emulsion tubes being wrong would effect how the bike comes on to the mains.

Did you have any of the carb parts that were removed when the kit was installed? or the jets from the kit?

I ask this because you should not really try to mix and match parts. So you would need to find out if anyone around you sells Dynojet jets or order some.

Either that or pick up some stock needles and slide springs.

i can try or should i see if any one has a diff jet kit, for now to keep riding i was thinking of just moving the clips to the number three spot it doesnt take me long to tare it apart i just enjoy riding to work so in that case i can keep it under the bad spot, so if it was yours would you start back to stock or what jet kit do you recomend

this is how i bought the bike i only took the carbs apart to clean them the bike sat for 6 years the first go around then the previous owner that had the work done took it to the shop to get it running and was still scared of riding so it sat for another three years then i bought it cleaned it up got it running and i have about 500 miles on it in the last three weeks and just been doing research to try to get it running perfect what ever that is?

also why do you think they did the third hole unlike yours is that going to hurt me in the long run

if i move the clip to the third slot it will reduce my fuel upon throttle right so it should not hurt any thing till i get it figured out right is how i am assuming it works?