Carb setup for open carbs

[Stu55]

Just thought I'd post an update on my NC30 track bike it's been work in progress for a few years but is now running spot on with open carbs, and no fuel pump.


DSC_1087 by Stu888, on Flickr

The spec is:

Mild gas flow to heads mainly on the inlets
No generator
Electric water pump
Modded carbs- 145 Mains, 4 extra holes drilled in emulsion tubes, 1.1mm washer on the needles, drilled slides, shortened trumpets, 3mm hole in air restrictor. This give a very smooth pickup and good top end with no spluttering etc, it took me three track days to get the jetting working as I'd rather do it that way than on the dyno.


DSC_1086 by Stu888, on Flickr

The Bike has a full HRC pipe on but runs with a sound restrictor in the exhaust can. Its also running a CBR600RR ohlins shock on the rear.

I got alot of the info on the carbs from various threads so thought it might help someone else to see a complete setup that is working well

[Neosophist]

Sounds like you've got it running well.

http://www.akhara.com/nc30/nc30hrccarb/

I don't know if you've seen this link but it has some good info about the speficis of the actual HRC kit setup. and how the needles and slides differ.

I take it your using stock needles with your setup?

[Stu55]

Thanks yes it was one of the places I got some info from.

The bike is still on stock needles and they seem to work well with the additional washers and emulsion tube changes. It pulls very clean and smooth. Forgot to mention the fuel tap has been modded to remove the vacuum pipe as per HRC mods. Not sure if it's that clear in the pic but it has a heat blanket under the carbs and an air inlet above the top rad just to keep the cool air in there.

[Tim400GB]

Glad to see this, cheers

I have pretty much the same setup on my bike but it has yet to be run