If you pm me (with your email address!) I can send a pdf file to anyone that's interested.

It's been slightly updated since this was posted (mostly typos!), but all the basics are still the same.

Excellent write up

Thanks Cam,
Karl

DataRacer wrote:

VfRTeddy wrote:great read dataracer now i wish there was a DIY guide for the NC24 carbs lol

Ben

Once you have the carbs off, the procedure is the same as nc30 carbs (except recommended jet sizes).

ahhh sweet cheers dataracer

Ben

Ok Cam!

Great guide.. lets make it NC21 / NC24 friendly :-) (called NC2x from here-on in)

The procedure is almost IDENTICAL.

Once you've taken off the tank and the airbox, the NC2x has 4 coils, 1 per cylinder due to the 180 firing order and not being able to use the wasted spark.

The NC2x has the two front coils on a mounting bracket infront of the carbs.. this is held on with 2 x 8mm bolts and must be removed before you can take off the choke cable and the carbs. Theres an earth tag that bolts to this bracket on the right hand side (sitting on the bike) so don't leave this off when you re-assemble.

The NC21 has 110 / 112 jets (front / Rear) and 4 / 5 hole emulsion tubes (front / rear) the NC24 has 115 jets (front / rear) and 4 / 5 hole emulsion tubes (front / rear)

The NC24 carb sliders have rounded bottoms and are very similar (if not the same) as the NC30 HRC items.

They have two air pressure holes for throttle response so they do not need drilling out like the smaller single hole NC30 sliders.

I'm not sure about the NC21 sliders... you'll have to check if they have 1 or two holes and the size of holes.

I've found that shimming the needles on the NC24 is also un-necessary, but ymmv. (they have a stock .5mm shim)

The pilot screws on the NC2x are best set at 2.5 turns out to start with and depending on if it bogs or hangs adjust in or out 1/4 of a turn each time and go from there.

2 - 3/8's seems ideal on a completely stock bike.

Everything else is the same. Ie. 35 pilot jet, mounting rubbers etc.

Good info Neo!

I agree that there may not be such a need on nc21/24's to raise the carb needles.

Just an afterthought for those who are leaving the carbs off for a while and dont want the rubber to warp. Put them in the freezer and that will stop the rubber from shrinking :)

brill!! just what i need

hi great article cam most useful only one thing getting carbs back on after er! jumping up n down on carbs to get back on for several hours i found that if you put front inlets on first and the rear rubbers half off the manifold sitting vertical the carbs line up and will go half in then push down gently they plopped in hope this save some of u a bit of time :stu

got the bike back from service this weekend with large bill and they said i had to go to dyno.
but the bike ran great above 7000 an stationary was also good
wit no money left i red this article
have done the part with xtra washer on the needles was scared off screwing things up so did not drill the slides the result was great
bike now revs clean trough

thanks a lot for sharing