jetting difficultys

[NC30V]

hi guys,
help required!!!
bought a jet kit for my project nc30
but a bit confused by the kit,
the kit is as follows
2 packs of needles 8zg and 8zf
2 packs of washers 0.5 and 1.0
front main jets 4 hole
rear main jets 5 hole
5 packs of jets 140, 142.5, 145, 147.5 and 150 each pack containing 2 jets

this tells me front and rear jets are differant sizes huh??
also which are best ones to fit??

cheers
kev

[Psychosomatic88]

I do believe that you should run different sizes in the front and rear.

IIRC you have the full tyga system with maggot end can? What about carbs/filter/airbox are they still standard?

[NC30V]

yeah running full tyga system with maggot can, hiflo filter, carbon airbox, standard carbs and nitrous oxide system, so this i what makes me think i will need to use the bigger jets but dont wanna have it running crap when only riding slow.

kev

[superlite]

You won't need to run jets that big if you're running any kind of airbox/filter set-up. HRC needles may also be a bit of overkill with that set-up. Add the nitrous in and you've got the potential for things to go bang. I wouldn't know where to start if it were my bike, but I sure as heel would be going for a rich set-up! I think you may have to sacrifice the low - mid range?

[CMSMJ1]

I would be very worried about it running too lean when nos is used.

Bring it to the dyno day and get a look see at it then?

[NC30V]

yeah im gonna come down there weather permiting. but think im gonna stick the 145 and 147.5's in her and see how she go's.
just unsure on needles????

i have been told that it will need lot's of fuel when i press the button... so im gonna need big ish jets. just dont want it to be lumpy when riding threw town.
i am putting thicker head gaskets on to make it more safe.... prevent blowing her up. plus not turning the gas up to full pressure.

kev

[superlite]

It'll run like a pig with those jets in. I understand that you have to sacifice some performance to ensure it doesn't run lean when you hit the button, but those jets are on the slightly bigger side of a full HRC open airbox, no filter set-up = not much fun under 6-7K.

Assuming that you'll be hitting the button at high revs, you shouldn't need to change the needles really. So maybe just go crazy on the jets. I don't know? Report back on your findings though!

[NC30V]

whitch jets would you recomend then? i just wanna try to keep as much low down power as possible but also want it go well when ye cane it! and as long as fuel flows well enough for the gas system im happy.

so i leave the needles stock then??

[superlite]

The way I see it is you want a standard low-mid range with that set-up to keep things running well. BUT, the nitrous will not like that! So if you jetted for your current set-up (taking the NOS out of the equation) you'd be looking at jets of around about 130ish - you wouldn't be rich enough for the NOS. The difference between the 8ZG and 8ZF needles is fairly minimal (in your context) and as NOS is generally used at the higher part of the rev range, it will be on the jet anyway. That said, I would defo take it to a dyno to check the air/fuel ratio! And I would go for 140ish+ jets to start with - sacrifice low-mid but ensure that it doesn't go pop.

[Cammo]

That setup is trouble.

Jetting the bike for nos and having it rideable without nos is virtually impossible. It will need to be so rich that I doubt it would rev out without nos.

Installing an injector at the front of the airbox (or under the filter somehow) working off a relayed microswitch would be the way to go, this way you can keep the carbs completely setup for riding without nos, and having an electronic control for fuel addition will make a hell of a lot more sense when it comes time to dyno tune!!

How much nos are you gonna put through it? hp?