So there is a difference between the 24 and 30 HRC slides, gunna have to go check mine now to see if i have the real thing. If the 24 slides are longer then will they open fully? To me logic says at WOT the 24 slides will leave a lip hence not giving full flow.

I have 24 slides in my HRC CV carbs and at WOT, there is no lip.

Ti bolts look lovely. I have been trying to resist going titanium on a lot of bolts as the cost creeps up very quickly, but damn they look good!

lukemillar wrote:I have 24 slides in my HRC CV carbs and at WOT, there is no lip.

Snap no lip when using nc24 slides in mine either but what i am intrigued about is why rick's slides only have one hole in them where every other set ive seen has two. But this is no bad thing as mine only ran 100% through mid range once we closed off one hole and drilled out the other to 2.5mm.
James

Both when blow down the vacuum pull fully back and go into the slide housing. So no restriction with either this will I guess lean up the midrange a little to help with a richer fuel mixture, so at wot nc30 and nc24 slide cause no restriction despite popular belief.

porndoguk wrote:Both when blow down the vacuum pull fully back and go into the slide housing. So no restriction with either this will I guess lean up the midrange a little to help with a richer fuel mixture, so at wot nc30 and nc24 slide cause no restriction despite popular belief.

Yeah I believe the shape of the nc24 slides assist with fuelling on the hrc setup rather than anything to do with airflow associated with the round slides. Just use them!

porndoguk wrote:Both when blow down the vacuum pull fully back and go into the slide housing. So no restriction with either this will I guess lean up the midrange a little to help with a richer fuel mixture, so at wot nc30 and nc24 slide cause no restriction despite popular belief.

As Cammo has mentioned, it isn't to do with restriction so much.

The NC24 has a rounded shape which causes the roof of the hole to have a rounded shape, the NC30 slide is flat which gives the roof of the hole a flat surface.

I can't remember the science behind it but it does affect the air-speed / path / flow or somethign slightly :D (*clearly not a mechanical engineer*)

porndoguk wrote:Titanium & NC24 goodness ahead,

fitted my NC24 slides, drilled the hole to 2.5mm to match the NC30 ones, whacked my Rick O needles in and put 1 0.5mm shim in, having a idle problem on Cylinder 3 so i hope the 0.5mm will lift the needles enough to make it idle better,

They later NC24 slides (and the ones you want) have two holes in them not one.. this is the same as having one 2.5mm hole. Do NOT drill these slides.. you'll ruin them.

They look like NC21 slides.. i'll check part numbers in a minute for you

You flat-spot is a strange problem.. I don't have it on any of my bikes and they are all stock.. the 30 I have over here doesn't have it with either a standard rear or Yamamoto system on it..

Carbs are 115/118 jets.. Jap emulsion tubes

Thorougly cleaned and pilots set to 2.15 turns out.

No shims under the needles, stock air-box etc. Only thing I did was drill the stock flat bottom slides to 2.5mm.

How are you valve clearances etc.

If your still having the flat spot i'd love to come and give you hand next time i'm about and try help you banish it once and for all :D

Did you ever try different carbs?

Slides are interesting.

All NC24's are listed as using

16111ML0724

NC21's are listed as using 16111ML0004

I think maybe they are NC21 slides... maybe the vaccum hole is the only difference but length would be an interesting factor too.

i guess as i say its to increase the amount of midrange air flow, to compensate for the 140-150ish size jets a full hrc spec would run, im hopping they will allow more air in to compensate for my rich midrange,

if the bike runs well ill be off to the dyno again, as i feel ive done all i can to improve things,
i had been trying different things and the best improvement i last made was remove the 1 shim and fit the RO needles which made the flast spot VERY small and almost unoticible unless i actually searched for it,

the next thing i tried was remove ALL shims and it ran like a bag of crap, misfiring from i guess lowering the needles to far,

since we last dynoed it mart ive fitted: and its now at:

Rick Oliver needles, (from standard ones)
1 x 0.5mm shims, (from 2 x 0.5mm) (did go without any but was shite idleing)

118 Rear 115 Front jets (from 120x118)

NC24 slides, drilled to 2.5mm Dia (from stock nc30 flatslides)

New 520 RK chain and renthal sprockets (15x40) did run a 14T but found it to high reving on Mway,
(from a Knackered 525 iris oring with stiff joints, standard honda sprockets 15x40T)

Full Tyga stainless system with a 450mm Carbon oval can,
(From standard headers, yamamoto rear, 330mm tyga oval stainless can)

the carbs have also had some new #35 pilot jets as my others were goofed
i gave them another once over, checked float heights, and gave everything a clean again,

so with a bit of luck ill be reaching the 59BHP mark with a nice fueling CURVE :D

the slides do pull all the way back, and dont restrict the venturi when i blow on the vacuum pipes,

Jim (Reverse cylinder) has the 2 holes NC24 slides and said that he sealed one hole off as he had problems with the 2, these slides came from Chownsy from some spare NC24 carbs he had but they could be from a 21?

either way i shall try and see what the crack is would love to know the size of the NC24 slides, i may but a post up to find out.

Valve clearances were all in tollerance when i last checked 12months ago, aprox 1000miles at most ago,
ill be doing them again soon and i will have them all set to the upper part of the tollerance.

Thats odd.. the two holes are smaller than the 2.5 hole and is the same as the genuine HRC slider setup.

Only speculation but perhaps his problems were something else that got fixed at the same time as removing and re-installing the slides.

59? Aim in the 60's :D

The UK one made 64ps I believe and that was only increased jetting and freer-flowing exhaust (not sure about ECU so don't know)

However, since you have a Yamamoto system / tyga can? (guess)

Hopefully you'll get a good figure.

Kev's bike and a few members on here at the dyno day with good condition NC's and half/full systems were seeing around 62-63hp so I think thats a resonable target for a stock-motor thats running well. :-)