Okay, I've 'aquired' a few NC21 carb spares that I'm trying to work out what to do with.

Let me just back track a little. I was working on a carbon carb bracket and velocity stacks, but that project has been scrapped due to numerous practical issues (for now anyway). So I'm looking at some options.

The NC21 carb bracket (I assume - carb numbers are a little hard to verify) is a lot bigger than the NC30 item (see pics). You can see in the pics that the NC21 bracket is quite different and would help or hinder performance - the question is which one? It looks a little similar to the RC30 carb bracket. I thought I might give it a run on my NC30 that has full HRC carbs (no airbox) and see what happens. I know what you're thinking: why bother? Well, because I can and I need another project to add to the hundreds I already have on the go!

Here's a question to the RC30 fans out there: Should I grind and drill it NC30 HRC style? I'm pretty sure that RC30s ran a standard carb bracket? There's been a bit of debate through the ages of grinding and drilling the carb bracket - weight loss or airflow?

Anyway, I'd be keen to here opinions from all and any who have one. Who needs ramair when you've got NC21 technology

Now as much as I love the forums, I feel as though the 'tech stuff' of old is a little lacking. Sooooooo, hold onto your seats for some serious NC30 needle analysis! Pretty much every Honda and HRC needle ever produced for the '30 - exciting, I know

NC30:


NC21:

good arrows on the tech points. I agree entirely. I will be testing some bakudan needles soon so will add them to the pot.

ref the bracket - I say drill it and grind it. weight loss I reckon as the carbs tray is only for bolting the airbox to.

If you could get away with it I would imagine not running a bracket at all would be the way to go.

plus..drilled stuff is cool

I think I've got some bakundan needles in my database. They don't seem logical to me though

They are a bit random for sure... Have you any of the jets too? They are strange.

Looking forwards to a techy bit of NC geekdom man - put your beer down and go get it sorted!!

superlite wrote:Now as much as I love the forums, I feel as though the 'tech stuff' of old is a little lacking. Sooooooo, hold onto your seats for some serious NC30 needle analysis! Pretty much every Honda and HRC needle ever produced for the '30 - exciting, I know

sweet man,i look forward to reading what you have to say about them

Good to hear that others are craving a little nerdery! I'll get some needle stuff up in the coming days. Here's some more tech stuff to keep you going.

Thought I'd post a pic of a carbon velocity stack (prototype). It's designed to fit my carbon carb bracket, so unfortunately won't fit a standard alu bracket. I've all but given up on this project for a number of reasons. The main reason is the difficulty involved of fitting the carbs with a carbon bracket - you can't stand on them! Aside from that, I've been molding with silicon (hate to wreck a genuine HRC bellmouth with resin!), which is a total b!tch. Anyway, they might see the light of day in the future, but for now I'm working on my carbon drenched Yamaha Chappy pit bike (priorities!).



@ CMS, just realised that you got the Bukudins off Stickshift, so I don't have any now I might have data on them still though. And yes, if I put my beer down I would probably take over the world - but thankfully for all, that's not about to happen :D

I know of at least two racers using no carb bracket and just some alu bracing (one CNC'd, one home job)- not sure though? One also runs NC35 carbs, which are a tad different. I just have a feeling that it also assists in directing air into the carbs.

Anyway, more to come soon.

I'll be interested to see just how close some of the hrc needles are to the std nc21/24 needles, they look to be very similar to the point of probably being able to run them with full hrc carbs.

I have a set of 24 needles here if you want any measurements?

Neosophist wrote:I have a set of 24 needles here if you want any measurements?

I've probably got some. What are they stamped with?

It's a little hard to ID some of the older carbs as the Haynes manual doesn't help much with the carb numbers.

superlite wrote: It's a little hard to ID some of the older carbs as the Haynes manual doesn't help much with the carb numbers.

I reckon the haynes manual is incorrect when it comes to numbers for the range of nc21/24 carbs.