Hi all,
Just wondering how others have modded their velocity stacks on the nc30 carbs. I want to run the HRC kit from Rick Oliver, but not sure the best way to trim the stacks.
I have an old set that i have started to trim, but it looks a bit messy.
Is there a better way?
Or just incase i am the luckiest guy in the world, does anyone have any for sale ?
Cheers

Here's a pic I found of some cut down standard stacks, the air jet on these doesn't look like it's been restricted:

Cheers Camo, looks a bit better than the job i have done, better get the scalple out on the decent set, make a better job of it
I have had a look for the pilot jets that you suggested for the air restrictor, but couldn't find any spare so will have to order some. Do they fit straight in or will the existing air tube need tapping?
Cheers

You'll need to tap them to take pilot jets.

Easiest to use the standard pilot jets (35's) for this and drill them out, as I imagine you'll be wanting to use bigger pilot jets for your carb setup (40's work well for me).

Cammo wrote:You'll need to tap them to take pilot jets.

Easiest to use the standard pilot jets (35's) for this and drill them out, as I imagine you'll be wanting to use bigger pilot jets for your carb setup (40's work well for me).

That sounds like a very good idea, cheers
Do you set your pilot jets as per before 2 turns out, or is it start at 2 and adjust as necessary?

That's the pilot screws, mine are set at 1.25 turns out.

I think 1.5 turns out is the setup example used in the hrc manual.

Cheers, Cammo.
I will have to see if i can get an English version of the HRC nc30 manual, mine is a japanese one. And for some reason i cant dowload the one from Akhara.com for some reason.

Just remembered that the base carb setting is in the TT-F3 manual, not the SS/SP manual on Mike's site.

You don't need an English translation, the carb settings are all readable. Can't remember them off the top of my head but will put them up here when I get home from work if you like.

TT-F3 manual:

Cammo wrote:Just remembered that the base carb setting is in the TT-F3 manual, not the SS/SP manual on Mike's site.

You don't need an English translation, the carb settings are all readable. Can't remember them off the top of my head but will put them up here when I get home from work if you like.

TT-F3 manual:

Cheers Cammo, thats very decent of you I owe you a pint...

A sharp exacto knife will do the job.

To start with, you want to cut the stack just above the bottom rib leaving a few mm of rubber above it. Then shave material off above the rib gradually as you're working your way around - until you get level with the top of the rib (this will be the top surface of the cut-down stack and allows you to put a nice internal curve on it). Then do the same on the inside until you get a nice curve. The trick is to take very small amounts of rubber off with each shave. You tend to loose a little bit of rubber where the airjet sits as it is very thin there when cut down.

Then sand with 400 grit (ish) wet and dry (dry) and finish with 1200 grit wet for a nice smooth and shiny finish. In the end, it doesn't have to be perfect, but smooth is good.

The pic below should give you a better idea - you can see how the rib allows you to make a nice internal curve.



Could have sent you a set a couple of weeks ago, but looks like I've binned 3 of them. Go figure