Rejet in progress...need a lil help

colin155 · Post by **colin155** » Mon Mar 28, 2005 11:12 pm

Hi,
after an airbox mod i'm rejetting my bike ( zxr 400 my97)..i think i'm very close to the good setting.. but. being so close also mean that is difficult to understand some situations..
so..... does anyone rejetted his bike after some kind of mod?

i'm running on 115 mains...and seems to be pretty good but i always fear to run lean ....

byye

RedexRobB · Post by **RedexRobB** » Mon Mar 28, 2005 11:38 pm

Theres a couple of guys on here that have mad that mod, solmansoft and il4 being the two i remember, so they will have more details for you.

Thing to remember tho its better to run lean then weak, the petrol is used to help cool the inlet valves as it passes, so running weak can cause over heating

Just to worry you some more

Post by **cargo** » Tue Mar 29, 2005 12:00 am

Exactly what changes have you made to your airbox

Mine is at the dyno right now after fitting a ramair system and I've got some base settings

colin155 · Post by **colin155** » Tue Mar 29, 2005 7:06 pm

for now i've removed the scoop and the rubber spout (sorry but remember english isn't my mothertongue) in the airbox intake.. fitter a fiberglass plate with "less restriction" velocity stacks

but.. this is a "try"... the dream is to fit a ram air like yours!

so.

if you want to tell me some... that would be great!

il4 · Post by **il4** » Sun Apr 17, 2005 5:04 am

colin155 wrote:for now i've removed the scoop and the rubber spout (sorry but remember english isn't my mothertongue) in the airbox intake.. fitter a fiberglass plate with "less restriction" velocity stacks

but.. this is a "try"... the dream is to fit a ram air like yours!

so. if you want to tell me some... that would be great!

Do you have a picture of your Velocity stacks for me to take a peep?

I have removed the air scoop in the air box....hence its grossly lean on the main.

I'm currently running on #120 mains, 0.5mm shimmed needles and #40 pilot jet.

The pilots jets are definitely out....the low end crap!

I juz had a track session on good friday, and i realise I'm still running slightly lean on the main jets, juz bought #122, i will keep u updated when it try them....

I'm from Singapore...

if you find my carburation unusual, maybe you can use the climate data of my country as reference

http://app.nea.gov.sg/cms/htdocs/article.asp?pid=1088

Guest · Post by **Guest** » Sun Apr 17, 2005 9:22 am

Hi!
i don't have pics..but i can make some! so.. write me a pm with your email and i'll send you the pics.

my bike has a similar "setup" but now i've fitted 130 mains ...

but i still got to test 'em ! i've just take a lil try the day i fitted em and.. no more..'cause still raining hard!

if you know where to found my climate data... i'm from nord italy

Guest · Post by **Guest** » Wed Apr 20, 2005 9:35 pm

Try emailing sloweracing he runs a http://www.bbplastics.co.uk ram air box on his race bike.

tk400 · Post by **tk400** » Mon Jun 06, 2005 3:03 am

Are you guys running air filters with those jet sizes?
I used to use 125's with no air cleaner and a deristricted airbox but am strugling to jet my flatslides with out the snorkel and with an aircleaner.

I would like to see the airbox mods and velocity stacks aswell
please

cheers

Post by **sloweracing** » Mon Jun 06, 2005 7:11 pm

Mine is a Race bike producing over 76 bhp so it's a bit different but should be same to set up so here is some tips

JETS 115 main

Blocked off air correctors

BB plastics air box ( http://www.bbplastics.co.uk )

If you block the air jet it settles the bike down and is easy to dyno setup
if you are running a mod air box i would block off the air jet and run a 100 or 110 main jet but would recomened a dyno run it's not good to keep guessing it could cost you a engine

Ram air box buy one you wont regret it then you can start playing with
stacks mine are still standard dont need the extra power at the moment
takes to long to get to a dyno and set up winter project for next season

Good luck

colin155 · Post by **colin155** » Mon Jun 06, 2005 8:44 pm

thank you mates!

i haven't never tried to block airjets.. anyway...maybe i've found the correct setup!
now i'm running 130 mains and the bike now seems to be perfect.. with lil jets the bike runs bad at full throttle...
reducing the airflow.. the bike became rich so... guess is right

colin155 · Post by **colin155** » Mon Jun 06, 2005 8:46 pm

tk400 wrote:Are you guys running air filters with those jet sizes?
I used to use 125's with no air cleaner and a deristricted airbox but am strugling to jet my flatslides with out the snorkel and with an aircleaner.

I would like to see the airbox mods and velocity stacks aswell
please

cheers

yep... i'm running stock airfilter on my bike!

tk400 · Post by **tk400** » Tue Jun 07, 2005 4:58 am

Still would be interested to see the velocity stack setup.
I would like to run shorter stacks because sp ones are longer than even the standard ones this is not working well with a four into one exhaust.
I would like a more peaky machine. I did read that some people cut the stacks flush with the top of airbox adapter.

Slowerracing, I have probably asked before on another site I think, but
have you got flatslides with that setup.
And am i correct in saying that by blocking the air jets you stop emulsification in the emulsiontubes therefore creating a denser fuel and hence you 115 jetting may well be equivalent to something much larger with out these blocked. Does this tactic stabilise the jetting because the emulsion system is a little inaccurate. And because the fuel is now denser(no emulification with air) does this mean you would need to drop the needles several clip positions.

PS SLowerracing that bike sounds like an absolute beast with that HP level it would compete with 600's!

cheers,

Post by **sloweracing** » Tue Jun 07, 2005 7:57 pm

It would if i could ride it harder there is alot of 400 in the bemsee chaimpionship producing good horespower

my jets sizes unblocked would be 132 main jet

No we cant run flatsides in bemsee

Didnt need to drop the needle as i am racing a H model and there dont have or i havent got ajustable needles just lucky really on the setup my dyno chart that i have is really good as well not sure if it is down to a very good engine tuner and the care and the time that has been taken to get the horse power out of the old girl

Brands hatch this weekend to do some more testing saturday and sunday
if any of you get bored pop along watch some racing and have a few beers