Lunchbox and Jetting, Quick questions!

[Jayke]

What exactly does it do though? I know it's air/fuel mixture but.... What part of the range does it effect?

And on what were talking about now, is the clutch lever meant to be really heavy? I mean....mine hurts sometimes to hold it in at traffic lights and short stops. Guessed it was just cause I came from a 125 clutch which was light as hell :p

Sent from my C6903 using Tapatalk

[Crasm]

The more turns out the more fuel allowed though every 1.5 turns is the eqivelant to goin up 1 jet size. And it controls idle and low rpm

My clutch is irrelevant lol i need to adjust the play cuz the cable has stretched and my bites about and inch from the handle bar and the rest is loose just saying i need to adjust it lol

[radodrill]

After riding mine in stop start  traffic today ive noticed at pull off with very low rpm and slipping the clutch that its a little hesitant before 1500 rpm but totally fine all through the rest of rhe rev range  is this just the pilot not getting enough fuel??

BTW: I generally set my idle around 1500 RPM

Radodrill - 4 turns on a 22.5 pilot? Bloody hell !!
Saying that my bike was 4 turns out on standard jetting so might give 4 turns out a try

Yep it perked up quite a bit going from 3 to 4 turns

What exactly does it do though? I know it's air/fuel mixture but.... What part of the range does it effect?

The mixture screw controls the size of the idle fuel port located between the engine's intake manifold and the butterfly valves.  This only affects the idle and how easy it is to start a cold engine at various temperatures.  Lean makes it hard to start at cold temperatures; while rich makes it hard to start at warmer temperatures, yet easier at colder temps.

[Jayke]

Very interesting, I'll have a play will that, then. I'm sure my valves clearances and tappets will be doing something too, they're loud as hell . Doing the carb needle/65 jets(hopefully) and valve/tappets tomorrow and Wednesday, will let you all know how it Goes, or badly. We will see lol!

Sent from my C6903 using Tapatalk

[Crasm]

Mines the same !! I think my valves and tappets need adjusting as they have gone noisy since the lunch box

[The Buddha]

Mines the same !! I think my valves and tappets need adjusting as they have gone noisy since the lunch box

Maybe not, you do hear some engine noise from the lunchbox. You'll get used to it. It sounds raspy. You can hear the air hissing in, and the engine noise coming out. I love that sound. However I'll never discourage someone from looking at their valves on a gs.

Cool.
Buddha.

[Crasm]

That might be it buddha.i can definatly hear all the air noises and alot mire mechanical noises that i didnt hear before the lunchbox was fitted.
Ive got no more poping and bangin on shut off and it needs alot less choke to get it to start from cold .
My set up is exactly what you recommended the only difference is im now 4 turns out on the mixture screws and im much happier with it than the 3 turns out.
But everything you explained to me was spot on and you helped me out massivly so thank you so much for all your help and advice and for being patient with my many questions its very much appreciated.

Also radodrill all your help and advice and explainations helped me out greatly and i thank you for all your help and advice.

And also just thanks to anyone else who contributed to the cause , your all kegends in uour own rights

[The Buddha]

With a lunch box the joke is - every time you open the throttle, you sand blast the top of your piston.
Cool.
Buddha.

[radodrill]

Well I'm going to be picking up a 25 pilot, 65 mid-main, and 150-160 mains so I'll be able to play around and get the optimal jetting for the new exhaust setup

[Jayke]

Just changed the needles,  managed to get the screw off thankfully. Taken a few pictures with my dslr. Will post them up later, time to reassemble and test her out!!!!

Sent from my C6903 using Tapatalk

[Crasm]

Well I'm going to be picking up a 25 pilot, 65 mid-main, and 150-160 mains so I'll be able to play around and get the optimal jetting for the new exhaust setup

What modifications you running to warrant jets of that size radodrill??
Your making me think mines still running lean lol

[The Buddha]

Just changed the needles,  managed to get the screw off thankfully. Taken a few pictures with my dslr. Will post them up later, time to reassemble and test her out!!!!

Sent from my C6903 using Tapatalk

Changed needles ? hopefully you kept the stock ones.
Cool.
Buddha.

[Jayke]

Alright, so I promised pictures of when I did the needle... So here goes:

Last time I dis-assembled the bike, finding the right pipes to go onto the different places on the petcock was a ball-ache, so I 'labelled' them in a ghetto but very effective way.

IMG_3452 by itsJayke, on Flickr

Once I'd done that, I removed the carb and removed the needle....

IMG_3439 by itsJayke, on Flickr

Here is the Needle, its a 5DH41 and this is how it was when I pulled it out, moved it down a notch like you guys suggested:

IMG_3442 by itsJayke, on Flickr

Then here are the needles, after is the one closer in the picture, as you'll see, it now doesn't stick out as much.

IMG_3450 by itsJayke, on Flickr

The VERDICT:

I have pull now from 6-10k rpm, how about that?

First thing I noticed was that the RPM's increased alot faster than usual and I had alot more usable power after 5k ish.

Again, I have no way of knowing whether this is correct.... but I'm going to set up my drift on the tank and do a few 0-60 runs of the bike as timing it any other way is hard for me right now.

This info only stands though with the 62.5s, may be better when I get the 65s I don't know.

Only bad thing I really noticed is that the bike sometimes bogs out when at 3.5-4k, though I went straight for 4 turns as Crasm thought it felt better; I may try 3.5 turns to see how it goes but that will be tomorrow!


>>>If you fancy any of the full res images for any reason e.g. the wiki, they can be found here:

https://www.flickr.com/photos/97659672@N03/sets/72157642210318835/

[Crasm]

Interesting

Your needles e clip was on the 2nd notch from top standard and you have moved it down 1 notch
To the 3rd from top.

Now

Mine was on the 3rd notch from top as standard and i moved it down 1 notch to 2nd from bottom

So your e clip was 1 notch higher than mine as standard , we have both moved down 1 notch
But im still 1 notch lower than you are

Interesting difference from an 01 to an 05 uk models

[Jayke]

Strange. Maybe one of the pros will have an explanation for that, but it's most likely stock, as getting them screws out of the top of the carbs was HARD! If they happened to be the same. One has been modified. Most likely mine lol, as they have messed with everything else....

Sent from my C6903 using Tapatalk

[radodrill]

Well I'm going to be picking up a 25 pilot, 65 mid-main, and 150-160 mains so I'll be able to play around and get the optimal jetting for the new exhaust setup

What modifications you running to warrant jets of that size radodrill??
Your making me think mines still running lean lol

Only performances modifications have been a K&N drop-in filter (without the restrictor ring) and custom fit exhaust.  After the filter change and before the exhaust I had it jetted perfectly at 20/60/142.5 with 2.75 turns.

The stock pipe had 30mm ID headers, 40mm ID right after the 2-into-1, then expanded to 50mm ID along the side of the swingarm to the can.

The new can is the back half of a Vance & Hines full exhaust; it is almost a straight pipe and was welded a 50mm ID link pipe.  The new headers are from an earlier GS500 that had 40mm ID tubes for the headers and from the 2-into-1 all the way to the stock can; I cut that at the  "mid-pipe" and swedged out the end to fit tightly into the V&H link pipe.

Currently I'm jetted to 22.5/62.5/147.5 4 turns and the idle and responsiveness seem pretty good, but at WOT it feels like it may still be running lean; hence an assortment of mains to play with.  I figured while I'm at it I'll give the 25 pilot and/or 65 mid-main to see how it behaves.  I'll certainly update once I've finalized my jetting.


In your case, if you step up a main size and don't lose WOT pull, then the previous jet was leaner than ideal; if the next size results in a loss in pull, the new jet is too rich.  You should find one main that gives you the best WOT pull; that will be the ideal main.

Interesting

Your needles e clip was on the 2nd notch from top standard and you have moved it down 1 notch
To the 3rd from top.

Now

Mine was on the 3rd notch from top as standard and i moved it down 1 notch to 2nd from bottom

So your e clip was 1 notch higher than mine as standard , we have both moved down 1 notch
But im still 1 notch lower than you are

Interesting difference from an 01 to an 05 uk models

Looking at the Suzuki service manual, the UK spec K5 model came stock with a 130 main and a 5DH57 needle at the 3rd clip position; the UK spec K1 had a 115 main and 5DH41 needle at the 2nd clip position.  So for the 05 you probably only need to adjust the clip position if there isn't a smooth transition passing through 6-7K at WOT.

[Jayke]

Ahhh that clears the needle problems up, then... I was confused, thought they were pretty much the same lol!

I will probably order some more tonight/tomorrow depending on what happens, right now I need a new chain and sprocket kit which will knock me back a good £80...

Probably just gonna order some 150s, 152.5 and possibly some 22.5 pilots, I think we need to find out which system the delkevic is like most, most likely V&H or Jardine I'm guessing.

[Jayke]

Just as an after thought.....


Theres one strange noise, that I don't really know what it is...

Its kind of like a spooling down noise(maybe this will help>>>>)... *wom* *wom* *wom* kind of noise when I stick at a certain rpm after acceleration.

Any ideas?

[Crasm]

I never tested it in the 3rd clip position i just dropped it to the 2nd while the carbs were off.
She seems fine but now you got me curious lol.
I turned the air mixture out to 4 turns and turned the idle down a little and to me it seems better.
Im going to check the plugs tomorrow and see what there saying

[BockinBboy]

Hard to know with actually hearing it, or pinpointing a location.  But I'll add a note about sounds.  I find that at about 5k rpm or so, things that may be a little loose, vibrate at the perfect resonance to create odd sounds... Noticed this first on my frame sliders (T-rex brand) when the crossbar started getting loose.  But I have noticed it on other things before too, like the bolt on the sidestand.  I don't mean to make it sound like my bike is rattling apart lol, but they were reminders to torque everything to spec again.

- Bboy