Jetting Thread

[Squishy]

Update..

So I kinda figured it out.
I tried without the airbox cover but no-go. WAY too lean would hardly go when opening the throttle.
So when I refitted the cover I figured to try and putting back the snorkel... and to my surprise the jerkiness at 8000-9000 rpm was almost completely gone. I guess it does have a purpose, at least on my bike.

The midrange has increased really noticeably too:
I made an acceleration video last month so today I went back to the same place and did another video.
Here's the result, 4th gear roll on 40-80km/h.
https://dl.dropboxusercontent.com/u/22072961/MF/Acc2.mp4

It still feels a little weaker at 8000rpm, but perhaps it only seems like that because the midrange is stronger.. not sure

[andrewsw]

snorkels serve a purpose, acting as a velocity stack and are often tuned to the appropriate resonant frequency (with the airbox) to do things like punch up the mid-range. While I don't know that this is the case with the b4 airbox, I wouldn't be surprised to learn that it is.

A

[Squishy]

snorkels serve a purpose, acting as a velocity stack and are often tuned to the appropriate resonant frequency (with the airbox) to do things like punch up the mid-range. While I don't know that this is the case with the b4 airbox, I wouldn't be surprised to learn that it is.

A

Well, in this topic Thief100 said he put it on the dyno with & without snorkel and without he got 0.5 extra HP without dips...
Mid range is the same with or without for me.. but jerkiness at 8000rpm is now gone and it pulls in 1 go.

Anyway, stock settings there would be a noticeable torque increase from 8000-12000 rpm. Now it's more like 10000-14000 and way stronger between 4000-8000.

Gonna see what happens with silencer again.

[Squishy]

What I do notice:

Some time ago I tried needle clips on richest position (+2, stock carbs). The midrange was strong but when I would open the throttle quickly from low RPM (about 2000rpm) it would start to stall. I would need to open the throttle more easily and it would go.
Putting it back to +1 rich settings would fix this but the mid range would be a a little weaker.

Now with 110 main jet (and +1 on the needle) this problem has returned. I assume because the main jet affects the whole range.
Is there any way to have the strong mid range but not the flooding/stalling from 2000rpm+full throttle?

Does the pilot screw affect this or does that really only affect idle? It starts and idles fine.

I didn't think the 110 main jet would change so much but damn it almost doesn't feel like a 400 anymore with this mid range.

Thanks

[T2098]

Does anyone have the specs or information about the stuff that comes in the Factory Pro 1.0 kit?

I bought the Config 30 kit and am running pod filters, but am considering going back to running the airbox - but I'd prefer not to have to buy the entire thing all over again, especially if the 1.0 kit contains similar needles.   Given that I already gave Factory Pro my money I was hoping that someone could share the info.  I can trade the Config 30 stuff. :)

[PALERO]

I've copied this Jetting format from Ninjette.org's 250 Jetting Database.

YEAR: 1992 Bandit GSF 400 USA

INTAKE MODIFICATIONS: K&N Pods RU-1824

EXHAUST MODIFICATIONS: Stock Exhaust, Cap Removed

JET KIT OR STOCK? DYNOJET Kit #3134 (Packaged as RoadKrome 12-9202)

BRAND OF JET KIT? DYNOJET

MAIN JET: 107.5 Mikuni Generic from JetsRUs.com

NEEDLE AND CLIP POSITION: Dynojet Needle, bottom clip (richest position, highest needle height)  Dynojet Supplied Springs

MIXTURE SCREW SETTINGS: 3

ELEVATION: sea level to 300 ft.

MISCELLANESOUS INFORMATION ABOUT YOUR BIKE’S JETTING SETUP: 0 throttle to 3/4 throttle response is fantastic, however bike doesn't not pull at all at WOT (full throttle.)  Bike "stands still" at WOT.  I do not recommend this setup.

[PALERO]

I've copied this Jetting format from Ninjette.org's 250 Jetting Database.

YEAR: 1992 Bandit GSF 400 USA

INTAKE MODIFICATIONS: K&N Pods RU-1824

EXHAUST MODIFICATIONS: Stock Exhaust, Cap Removed

JET KIT OR STOCK? DYNOJET Kit #3134 (Packaged as RoadKrome 12-9202)

BRAND OF JET KIT? DYNOJET

MAIN JET: 110 Mikuni Generic from JetsRUs.com

NEEDLE AND CLIP POSITION: Dynojet Needle, bottom clip (richest position, highest needle height)  Dynojet Supplied Springs

MIXTURE SCREW SETTINGS: 2.25

ELEVATION: sea level to 300 ft.

MISCELLANESOUS INFORMATION ABOUT YOUR BIKE’S JETTING SETUP: WOT pull is fantastic and fast.  0 to 3/4 throttle motor stumbles, then accelerates.  Bike is just OKAY, but I miss the 0-3/4 throttle performance of 107.5s and bottom clip.

[PALERO]

I've copied this Jetting format from Ninjette.org's 250 Jetting Database.

YEAR: 1992 Bandit GSF 400 USA

INTAKE MODIFICATIONS: K&N Pods RU-1824

EXHAUST MODIFICATIONS: Stock Exhaust, Cap Removed

JET KIT OR STOCK? DYNOJET Kit #3134 (Packaged as RoadKrome 12-9202)

BRAND OF JET KIT? DYNOJET

MAIN JET: 110 Mikuni Generic from JetsRUs.com

NEEDLE AND CLIP POSITION: Dynojet Needle, 3rd clip (middle position, middle needle height)  Dynojet Supplied Springs

MIXTURE SCREW SETTINGS: 2.25

ELEVATION: sea level to 300 ft.

MISCELLANESOUS INFORMATION ABOUT YOUR BIKE’S JETTING SETUP: WOT is fine.  Bike seems to bog at middle clip.

[PALERO]

I've copied this Jetting format from Ninjette.org's 250 Jetting Database.

YEAR: 1992 Bandit GSF 400 USA

INTAKE MODIFICATIONS: K&N Pods RU-1824

EXHAUST MODIFICATIONS: Stock Exhaust, Cap Removed

JET KIT OR STOCK? DYNOJET Kit #3134 (Packaged as RoadKrome 12-9202)

BRAND OF JET KIT? DYNOJET

MAIN JET: 110 Mikuni Generic from JetsRUs.com

NEEDLE AND CLIP POSITION: Dynojet Needle, 2nd clip (2nd richest position, 2nd highest needle height)  Dynojet Supplied Springs

MIXTURE SCREW SETTINGS: 2.25

ELEVATION: sea level to 300 ft.

MISCELLANESOUS INFORMATION ABOUT YOUR BIKE’S JETTING SETUP: 1/4 throttle to 3/4 throttle response is better than 3rd clip positionm, but still sputters.
WOT seems slow. 

[PALERO]

I've copied this Jetting format from Ninjette.org's 250 Jetting Database.

YEAR: 1992 Bandit GSF 400 USA

INTAKE MODIFICATIONS: K&N Pods RU-1824

EXHAUST MODIFICATIONS: Stock Exhaust, Cap Removed

JET KIT OR STOCK? DYNOJET Kit #3134 (Packaged as RoadKrome 12-9202)

BRAND OF JET KIT? DYNOJET

MAIN JET: 112.5 Mikuni Generic from JetsRUs.com

NEEDLE AND CLIP POSITION: Dynojet Needle, 2nd clip (2nd richest position, 2nd highest needle height)  Dynojet Supplied Springs

MIXTURE SCREW SETTINGS: 3.0

ELEVATION: sea level to 300 ft.

MISCELLANESOUS INFORMATION ABOUT YOUR BIKE’S JETTING SETUP: WOT improved.  Pulls now, but I think I will try 115s and see if pull gets better.

[Gouraami]

I hope you don't mind Pelero, I copied your copied template 

YEAR: 1991 Bandit GSF 400 Limited Mikuni BST33 carbs

INTAKE MODIFICATIONS: none

EXHAUST MODIFICATIONS: A differnt canister, large diameter

JET KIT OR STOCK? Stock

BRAND OF JET KIT? Stock

MAIN JET: Mikuni 108 off Aliexpress   

NEEDLE AND CLIP POSITION: stock needle 2nd clip position (richer)

MIXTURE SCREW SETTINGS: 1.75 turns

ELEVATION: sea level

MISCELLANESOUS INFORMATION ABOUT YOUR BIKE’S JETTING SETUP: I tried 110 main jets, but at WOT acceleration felt flat. No hesitation in mid range. Then tried the 108's, WOT much better, put a  on my face. Slight hesitation at 6000rpm at WOT. I plan to order 105's to check if WOT can be improved even more