I just put the yoshimura full system (old school) and a k&n lunchbox on my bike. I replaced various Orings in the carbs and looked at all the components and they all look fine.

I ordered the 150main, 40 pilot as per the jetting matrix, which most people were using for performance exhaust and lunchbox.

I am having a few problems, Switced to the 147.5 mains hoping for overall improvment, it really only improved the top end.

Currently this is how it is set up.

Mixture screws: 3 turns out
Pilot jet: size 40
Float height: right above the base of the gasket surface near the middle of the carb
Main jet: 147.5
Needle jet: My bike had needle jets with 5 clips on them, not sure if they are stock? Currently at the 2nd clip from the bottom.

Symptoms:
Pulls GREAT from 8.5-11k RPM at full throttle in all gears.
Stumbles from ~4-8.5k RPM at full throttle, it feels like it is bogging, it pops and spits.
Will NOT really go above 6k in 6th gear, it just bogs with more throttle and slows down.
Partial throttle at lower speeds in the midrange feels ok, but a little bit weak.

Any suggestions on what to change first?

Ill pull a plug tomorrow and look at that. I think it is running rich in the midrange.. but Im not sure what to change to see a better result.

Thanks

Quote from: slowinthestraights on August 07, 2007, 12:51:56 AM
Needle jet: My bike had needle jets with 5 clips on them, not sure if they are stock?

Adjustable needles = aftermarket.  Could be Factory; I believe Dynojet has 6 grooves.   Whichever, it's been reported Factory Stage-3 uses 140 main jets while Dynojet goes up to 134.  Your choice is to either go back to stock needles and use your current jetting or to keep the adjustables and go down to the appropriate MJ. 

What size were the main jets you took out?

Quote from: Gisser on August 07, 2007, 11:37:19 PM

Quote from: slowinthestraights on August 07, 2007, 12:51:56 AM
Needle jet: My bike had needle jets with 5 clips on them, not sure if they are stock?

Adjustable needles = aftermarket.  Could be Factory; I believe Dynojet has 6 grooves.    Whichever, it's been reported Factory Stage-3 uses 140 main jets while Dynojet goes up to 134.  Your choice is to either go back to stock needles and use your current jetting or to keep the adjustables and go down to the appropriate MJ. 

What size were the main jets you took out?

Why are you asking ? I was more looking for input on what I need to change to improve the midrange, but I am getting it now I think.  The mainjet already seems to be good, it pulls well in the higher rpms at full throttle (as stated).

The jets in it were 125s .. with stock everything.

With what you have already, the easiest fix would probably be to get stock needles and buy some #4 washers to shim them.  If the needle is dynojet, you could spend forever trying to get midrange with no luck.  That is what happened to me at least.  Buy needles and shim them via the jetting index and you should see improvement.  May not be perfect, but it'll be a ton better than it is now.  Bikebandit.com is a good place to get the needles, or you could go to a local dealer.

John

adjustable needles (5 positions) came stock on gs's from other places like Canada and Europe.  not sure where you're located or where the bike originates from, but just an fyi.

Your best bet is to throw a picture up of the needle, Dynojet needles have a funny taper.

So your first problem is you have to find out if your lean or rich(my guess would be rich) and to do that you need just to pull the plugs, if they are really dark and sooty(rich) or if they are white(lean)

Then you can go from there

Quote from: coll0412 on August 09, 2007, 08:57:02 AM
Your best bet is to throw a picture up of the needle, Dynojet needles have a funny taper.

So your first problem is you have to find out if your lean or rich(my guess would be rich) and to do that you need just to pull the plugs, if they are really dark and sooty(rich) or if they are white(lean)

Then you can go from there

Bike is from the US

I think I am still rich.. I have been moving the clip UP on the needle.. right now it is at the 2nd position from the top (that was a typo in the first post, it was originally at the 2nd clip from the bottom) and it is getting better midrange everytime i go up, but still misfires under full throttle. I am about to put it up to the highest clip, The top range feels very good right now, which is why I do not want to step down a mainjet, but I am going to do taht and see how it feels, to a 145 main. The needles have 5 clips, not 6 like dynojet needles apparently have.

Sounds like your on the right track, and remember that the jetting matrix is just what worked for someone else, and you may have to fiddle with the main to get it to work for your bike and your conditions.