fitted jet kit to 98 zx9r + dyno graph

[Nanna10r]

Been reading with interest mate. good stuff.
Cheers Brett

[MadKaw]

You could try scuffing up the metal plates with some rough sand paper or similar.

My clutch would slip in 4th at about 9000 rpm and it was all within the Kawi specs. I put in a set of Barnett springs and it was fine.

[SocialSecurity]

Been reading with interest mate. good stuff.
Cheers Brett

thanks mate... just remember, later model 9R's jet differently to 98/99 9R's incase your gonna have a play


as for the clutch, how much did the springs set you back madkaw?


if its still slipping i might give all the plates a little scuffing, and i might shim up the springs too

[MadKaw]

The Barnett springs were about $45 a set from Serco...

[SocialSecurity]

spent half an hour "machining" some 10mm washers to fit under the existing washers for the clutch springs... chucked em in and no more slip, lever doesnt feel any different... case closed as far as im concerned


the bike sure boogies now, tho i think it definately needs a half a needle clips adjustment... trouble is im not sure which way probably richer.. doesnt affect top end, just a slight flat spot around 5ish


hopefully have it sorted before PI, friday next week

[NinjaMoses]

Sorry for the thread hijack but just wondering...

I have a 98 ZX9 also and am picking up a full Devil exhaust system for it next weekend. I've been looking at getting a +4 igntion advancer, K&N filter and factory pro jet kit to fit along with it.

Is the factory pro jet kit worth getting? I'm a bit confused by the posts in here, are you saying the jet kit comes with 142 mains but they were no good and you had to swap to much bigger ones? Or does the factory pro jet kit come with many different sized main jets?

I didnt realise the stock headers even had a clean air injection type system (I just have a yoshi slip on at the moment on stock headers). I'm guessing the Devil system wont have this though so will be blocking it off also?

Guess I will start with the settings you are using and will go from there.

thanks guys,

Ninjamoses

[SocialSecurity]

your hijacking is welcomed

the jet kit didnt come with 142's, but somebody had fitted them to my bike previously (must have performed worse than with stock jetting)


the jet kit comes with a pair of 150's, 152's, 158's, 160's, 165's and 168's ... it expects you to still have the 155's fitted to the bike as stock (i didnt so i had to go buy a set)


ive heard dynojet jetkits aint so great, and that ivans are very good for 9R's especially if your running an akra or stock system... both ivans and factory give very good aftersales service and can give plenty of tuning advice too. can definately recommend the factory jetkit and factory +4 advancer tho. I would go with which ever you can get cheaper and easier. I have not got a K&N tho (just pulled the mesh from the stock filter) so dont copy my settings too closely, you'll need bigger mains, richer needles, richer floats and richer pilot screws... try the settings madkaw used on his race bike

what ever kit you do get, study this page very closely as there is no better tuning guide, follow it down to the letter. you'll develop a pretty good feeling for the bikes power band and how & where all the changes you make affect the bike



the clean air injection isnt actually in the headers, it squirts the air into the exhaust port through the head depending on vaccum... definately best removed (block or join the bungs comming out of the rocker cover, the pipe comming out of the airbox and the vacuum lines comming out of the head)



as for my settings, i have since made the bike a half notch richer with very good results, bike has a stonking midrange again and great top end, but the floats are set way too rich so its cactus below about 4k...


i have a sneaking suspicion that its running slightly better on cold nights compared to hot days.... i know the floats are slightly rich but it feels better across the board at night, not sure if i still need to go down a little on the mains or if adjusting the floats should fix everything (currently on 14mm need more like 16mm) .... will get around to sorting the floats and then if its still better on a cold night i might try staggered 155/152 mains .... currently all 155's and 3.5 notches from the top on the needles

[SocialSecurity]

just saw this....


http://www.muzzys.com/ZX998/index.html


anybody fitted it?

[MadKaw]

TKA ran em in 02 / 03 and from what I heard they were a lot of trouble.

The 01 TKA zx9r ran KLX300 pistons and was a 972cc. It was more reliable than the 02 model..

[SocialSecurity]

hmmmm, wonder what a new set of sleeves to suit the pistons would cost....

[SocialSecurity]

well, jetting is almost 100%

dropped down to staggered 155 (inner) and 152 (outer) main jets and hey hey - crazy power. midrange is really violent now too, using 2nd clip from the top on the needles.

the bottom end tho, i just cant get perfect power doesnt come on hard until 4k, and is very fluffy below then... no matter what i set the floats to. oh well, ill just have to live above 4k

[Phil]

well, jetting is almost 100%

dropped down to staggered 155 (inner) and 152 (outer) main jets and hey hey - crazy power. midrange is really violent now too, using 2nd clip from the top on the needles.

the bottom end tho, i just cant get perfect power doesnt come on hard until 4k, and is very fluffy below then... no matter what i set the floats to. oh well, ill just have to live above 4k

the torque kicks in around 4 , mine is totally ride able under that tho too

[SocialSecurity]

this really is fluffy down low tho, not so much in first or second cause the revs come up too quick... but rolling along in a higher gear around3k and cranking the throttle open, nothing really happens till it gets close to 4k...


when the bike had overly small mains (150/152 staggered) and the needles set to leanest with 13mm float height, it would power on at 3k like a rocket

[stevew_zzr]

Still could be timing related.

Carburettors don't atomise the charge very well, so *generally* speaking the mixture will burn slower (and possibly less completely) so if your timing isn't advanced (at lower rpm) - given the reasonably lean 'stock' fuel curve that you posted earlier - I'd imagine that you are constantly going to be compromising between top end power, and mid-range punch. Unless you get a more robust/programmable ignition system ?

Generally an air:fuel ratio of around 11.8:1 is considered ideal for making the most power at full load. Although the stoichiometric ratio is approx. 14.6:1 the mixture generally burns far too quickly and the flame front catches up with the piston, basically meaning that more heat is absorbed by the piston rather than by the air. Then you have to adjust the timing to suit get rid of detonation.

[SocialSecurity]

ive come to the conclusion that timing could well be half the trouble right now.... im running a +4 degree timing advancer and have been running the bike on normal 91 octane unleaded the whole time... set the floats to 14mm and the bike seems lean, almost like its pinging.... set the floats to 13mm and the bike seems really doughy, like its too rich... set it to 13.5mm and its just flat around 3-4k, no nasty vibrations no shuddering just flat.... perhaps +4 degrees timing is just too much to ask of 91 octane fuel? maybe its pinging at the 'ideal' fuel ratio, richen it up to stop it pinging and then its too rich.... also notice it runs much hotter than it should too... tho my cooling system is in tatters

gonna fill her up with some premium on pay day (im broke now and the tanks full of unleaded) but for the mean time ive pulled the advancer out and put the stock rotor back in and now it feels much different... not quite as snappy to the throttle, but a lot smoother... and in first the wheel didnt just come up like it normally does around 6k, it lept for the sky so i think ive found my issue... about to fire an email off to Marc Salvisberg from factory pro for a second oppinion


as for ideal ratios, 11.8:1 sounds more ideal for a turbocharged vehicle that has problems with detonation (mostly due to backpressure and high inlet temps) .... most dyno tuners ive spoken to say high 12's low 13's are ideal for peak power...

but on that note, speak to marc and he'll say that 'tuning to a ratio' is a waste of time... and hes right... you tune to best power (on n/a's any way)