NC30 carby jetting - DIY guide

[999Gomerz]

1- Would it be easier to continue oon the HRC tray route? What would I need?

Do you mean the full hrc open carb setup?

You'll need a replica hrc jet kit (from Rick Oliver) and you'll need to restrict the air jets as the nc30 hrc velocity stacks (which shroud the air jet) are no longer available. Not difficult, but some trial and error involved in finding the right restrictor/main jet size. Check out Jim's build thread for some info on a replica hrc setup: viewtopic.php?f=62&t=23105&start=30

Good info also at Mike's site: http://www.akhara.com/nc30/nc30hrccarb/index.html

2- Do I need the rubber flappy bits and the inlet duct for the oem airbox?

Difficult to say for a track bike. Certainly a must for a road bike if you want ease of carb set up, both of these parts are critical, many threads on here about problems when these are removed! I think it would be a good idea to try and get hold of both parts. Your setup is so out of whack currently that having these parts will get a much better result much quicker than without them!

Thanks Cammo,

I am going to get the original stuff and get it to a known level so I have posted a WANTED add in the section. See here if anyone has these bits I would really appreciate it [/url]viewtopic.php?f=16&t=26870[url]

Then see how it goes after that.

Will Keep you posted. (Maybe not in this thread as I dont want to fill it up with my crap.

Cheers,

[TheRehabKid]

I finished setting up my carbs and the bike runs so much smoother now, cheers for the help Cammo!
To sum it up, my bike runs a high flowing exhaust (with baffle in though) and UK carbs, before the rejet i was running 115f jets and 117.5r and had a terrrible flat spot from 8-9k revs and bogged down when trying to accelerate, rejetted to 120f and 122r and the bike runs perfectly now, pulls like a train through all the gears
I didn't drill a bigger hole in the slides as the UK ones already have 2 holes in, and no washers under the needles either. Seems to run best without any washers!

[yazza54]

Is there a balancing guide?

This is brilliant BTW

[martycochrane]

Hey guys, I Own a UK NC30 and followed this guide to help me replace the jets on my bike. WHen i was replacing them i realised that the owner before me had the front and back jets and needles mixed up which would explain why it was bogging down. I changed them around and now the bike is idleing really high (sounds like the choke is on). Any advice on what i should do?

[Drunkn Munky]

Hey guys, I Own a UK NC30 and followed this guide to help me replace the jets on my bike. WHen i was replacing them i realised that the owner before me had the front and back jets and needles mixed up which would explain why it was bogging down. I changed them around and now the bike is idleing really high (sounds like the choke is on). Any advice on what i should do?

Turn the idle speed down

[martycochrane]

Hey guys, I Own a UK NC30 and followed this guide to help me replace the jets on my bike. WHen i was replacing them i realised that the owner before me had the front and back jets and needles mixed up which would explain why it was bogging down. I changed them around and now the bike is idleing really high (sounds like the choke is on). Any advice on what i should do?

Turn the idle speed down

The idle speed adjuster that sits beside the choke is turned all the way out

[Man_Named_Dave]

The idle speed adjuster that sits beside the choke is turned all the way out

I'd check the operation of the choke, ie are the rods moving back and forth if you open and close the choke? Is the cable snagged?

[yazza54]

Just had the same thing, jetted up and refitted. At first I had a carb with a slight leak on a rubber which made the idle high. Sorted that and balanced it by eye and it's idling at 1.5k now. I'll balance it properly tomorrow with the carb pro. (cba now, just got back from my cbt -passed yippiee)

[DrunkenMistake]

Sorry if this has been covered, but what size holes should the washers be? I dont want to have to pull the carbs apart to get a washer for a rough idea of the size, then reassemble so I can ride into the city to get some washers haha

[thebugser]

I just stripped my carbs down and cleaned the jetting and float. I've refitted the carbs back on with new mounting rubbers and all went well. I can get the bike running with the air box off using a spray of easy start down each inlet and a temporary fuel supply. it won't start with the air box and filter on. Curiously whilst running fuel started coming up the rear cylinder head breather tube and spraying all over the place! what's going on? Any suggestions? Regards Pete