Needle Adjustment

[Cheriff]

So before I installed my Ivan's jet kit, my Kat had that annoying vibration around 5000-5200 RPMs. After installing it, that vibe went away. Now the vibe has come back - which I presume is because I cleaned up the welds on my header this spring. So I'm thinking that originally (as purchased) the bike was a little lean with the slip-on exhaust and the jet kit richened it up. Now with a little more air flowing I might be slightly lean again. I'm thinking that I need to adjust needles up a clip (probably a half first) to try getting rid of the vibe. First, does this sound reasonable, second is moving the clip up on the needle the right direction to go?

(Can't remember the number of turns, but my A/F screws are already out to 3.5 or 4. Whatever it was that Ivan recommended).

[Kreylyn]

Counting down from the top...

1 leanest

4 or 5 richest (depending on what brand you have)

Lowes has #4 brass flat washers btw that fit just right for shimming them.

Krey

[Kfreak]

So raising the needle richens the mix.

[Cheriff]

Thanks

[Cheriff]

So today I finally got around to playing with the needle height in my attempts to get rid of my 5k vibration. Short story is that it didn't work. Tried first removing the shim/washer.. no difference. Then lowered the clip/raised the needle one full notch and still no difference. So now the needle is set to the highest position (was at 1.5 notches from the highest as directed by Ivan).

So now I am kind of at a loss. I guess I could try synching it up again - maybe that would help. I am open to suggestions. Anything special happening at 5k that could point me in the right direction??

[Kreylyn]

So today I finally got around to playing with the needle height in my attempts to get rid of my 5k vibration. Short story is that it didn't work. Tried first removing the shim/washer.. no difference. Then lowered the clip/raised the needle one full notch and still no difference. So now the needle is set to the highest position (was at 1.5 notches from the highest as directed by Ivan).

So now I am kind of at a loss. I guess I could try synching it up again - maybe that would help. I am open to suggestions. Anything special happening at 5k that could point me in the right direction??

Check your emulsion tubes. If you have seen no effect on adjusting your needles, then the tubes they sit in may be worn and not functioning as designed.

I replaced mine and it made a HUGE difference not only in performance, getting rid of a nasty hesitation at 4-5.5k rpms, but I now see that my MPG has gone up by about estimated 20mpg MORE than what it was before (32 avg to 52+ avg now)

edit: http://www.factorypro.com/tech/needle_jet_wear.html this might help you to understand what I mean by "worn".

Krey

[Cheriff]

I should clarify a little.. by 'no difference' I mean the vibration didn't go away. I did notice an improvement with my butt dyno and after moving the needle one full clip I noticed that when I grabbed a hand full of throttle suddenly that there was a very slight hesitation before it took off - never had that hesitation before. So I was seeing some effects of moving the needle height. I don't know if they were as significant as they should have been, but there was some changes.

Question: The washer spacer to make height adustments - where does that go? On top of the clip or under it? I was the one that installed the kit originally and found that the washer was sitting on top of the clip (away from the pointy end of the needle). This seems like it is on the wrong side to be doing anything. Just like it is a good place to store it so it doesn't get lost. To actually raise it, wouldn't it have to be under the clip?


Just to recap: As purchased the bike had that annoying vibration around 5k. Installed jet kit, vibration went away. Last winter I opened up the header welds and the vibration has returned. It has been my theory that I need to add more fuel to the mix to get rid of it again. Should the next step be to back the a/f screws out to 4.25 instead of the recommended 4 (from Ivan) and put the needles back to their original position?

[Tmod]

I should clarify a little.. by 'no difference' I mean the vibration didn't go away. I did notice an improvement with my butt dyno and after moving the needle one full clip I noticed that when I grabbed a hand full of throttle suddenly that there was a very slight hesitation before it took off - never had that hesitation before. So I was seeing some effects of moving the needle height. I don't know if they were as significant as they should have been, but there was some changes.

Question: The washer spacer to make height adustments - where does that go? On top of the clip or under it? I was the one that installed the kit originally and found that the washer was sitting on top of the clip (away from the pointy end of the needle). This seems like it is on the wrong side to be doing anything. Just like it is a good place to store it so it doesn't get lost. To actually raise it, wouldn't it have to be under the clip?


Just to recap: As purchased the bike had that annoying vibration around 5k. Installed jet kit, vibration went away. Last winter I opened up the header welds and the vibration has returned. It has been my theory that I need to add more fuel to the mix to get rid of it again. Should the next step be to back the a/f screws out to 4.25 instead of the recommended 4 (from Ivan) and put the needles back to their original position?

When the washer is on top of the needle that is the storage position, You would add the washer under the clip to gain that 1/2 groove setting. So if the needle clip is on groove #3 and you put the washer under the clip you would now be at # 3 1/2 on the clip setting.

As far as the A/F screw if you are going to run it out much further get yourself a one step richer pilot jet and that way the screw won't need to be out that far, If memory serves correct Ivan states use a #15 pilot jet but I noticed on my 750 that is is running a 12.5 so that would make it a bit lean.

Tmod

[Suzukii600]

i got a question as i am having some problems with the mentioned nasty hesitations.... as far as the a/f screw... if i turn it to the left that makes it richer and to the right makes it leaner correct?

[Tmod]

i got a question as i am having some problems with the mentioned nasty hesitations.... as far as the a/f screw... if i turn it to the left that makes it richer and to the right makes it leaner correct?

After looking at your garage I see you have the K&N and the DJ stage 1, I am going to say get used to it as that combo leaves alot to be desired.

Tmod

[Suzukii600]

that didnt answer my question though so thanks for not helping?

[Cheriff]

So I tried calling Ivan and he said that he never tried the kit with the exhaust welds removed so he can't give me a good answer. Like we are suspecting the ratio probably needs more fuel added so he first suggesting lifting the needle a 1/2 to 1 position and then try a larger pilot jet.

Pretty much the advice I got from here already

So tonight I will put the spacer back in which in hopes of eliminating my tiny hesitation which would still leave it 1/2 setting higher than it was. I will ride it around a little this way (few weeks) to really appreciate the effects. If its still there I will look into the larger pilot. He recommended a company called Sudco.

Thanks for the help guys, you were spot on

[Tmod]

So I tried calling Ivan and he said that he never tried the kit with the exhaust welds removed so he can't give me a good answer. Like we are suspecting the ratio probably needs more fuel added so he first suggesting lifting the needle a 1/2 to 1 position and then try a larger pilot jet.

Pretty much the advice I got from here already

So tonight I will put the spacer back in which in hopes of eliminating my tiny hesitation which would still leave it 1/2 setting higher than it was. I will ride it around a little this way (few weeks) to really appreciate the effects. If its still there I will look into the larger pilot. He recommended a company called Sudco.

Thanks for the help guys, you were spot on

Do your carbs have the 12.5 pilot as well? I asked Ivan why he said the #15's were stock when we have the 12.5 as stock and he had no answer. I noitced the same as you that even with the Ivan jet kit you still get alot of vibration if you remove the welds on the header. I guess his kit is bone stock with zero mods.

Tmod

[Kreylyn]

that didnt answer my question though so thanks for not helping?

Ah, but he DID answer the question, you either just didn't like the reality of the answer or you choose not to read between the lines as he was trying to be nice about it.

Just incase it was the later, I'll state it a little more clear...

The combination of parts you used to modify your bike presents a scenario that is damn near impossible to tune and run right across all rpms. This is because they suck, meaning they are not designed specifically to work on the bike you put them on but on other bikes. But, since other bikes use similiar components, they have marketed them to you suggesting they will work... and you bought them.

The resolution to your issues would be replace your jetkit needles and put the stock airbox and filter back on, OR.... spend the next few weeks tuning and tweaking it everyday until you figure out what most others felt was not worth the effort to do with poorly designed parts for a Katana.

Krey

[Suzukii600]

Ah, but he DID answer the question, you either just didn't like the reality of the answer or you choose not to read between the lines as he was trying to be nice about it.

Just incase it was the later, I'll state it a little more clear...

The combination of parts you used to modify your bike presents a scenario that is damn near impossible to tune and run right across all rpms. This is because they suck, meaning they are not designed specifically to work on the bike you put them on but on other bikes. But, since other bikes use similiar components, they have marketed them to you suggesting they will work... and you bought them.

The resolution to your issues would be replace your jetkit needles and put the stock airbox and filter back on, OR.... spend the next few weeks tuning and tweaking it everyday until you figure out what most others felt was not worth the effort to do with poorly designed parts for a Katana.

Krey

im so confused, cause i simply asked which direction to turn the a/f screws to make it leaner or richer, not why i have a hesitation and how to fix the problem, i am more than happy to spend the next week making adjustments, sorry if my ambition to make do with what i have already is not welcome