Carb Cleanup

[NC35!]

Hi,

After seeing this site linked to elsewhere http://www.chrisgoddard.net/projectNC30page4#carb" onclick="window.open(this.href);return false; I am curious about cleaning the carbs.

To quote the website :

"The carburettors must be due an overhaul at this age, so they get a nice soak in paraffin, and a thorough clean out."

Does this soak in paraffin mean quite literally remove them from the bike and submerge them in paraffin? Or should I remove any parts first?

Thanks!

[V4Chris]

I did a partial strip down, removing everything you see in this picture,



before then putting the carbs into a bowl and pouring parafin on them. I did not have enough to completely submerge, but enough to get a good soaking and then brush all the internal surfaces reachable with a toothbrush to remove deposits.

You can get a similar result without removing anything from the bike using a petrol additive such as Redex. I chose the above route because I was also altering the jetting.

[Neosophist]

Yes, it means remove them.

Parafin shouldn't really harm anything but it's best to strip them down if your doing a complete service as if there is any junk / gunge that is in the carbs it might not be able to make its way out.

After soaking / scrubbing in parafin blow through all of the holes with some compressed air to make sure they are clear.

[superlite]

I did a partial strip down, removing everything you see in this picture

Even the floats, I'm impressed!

Actually, I have been supriseed by the amount of varnish that forms around the float valves. Not on my pristine carbs of course, but on older NC21/24 carbs. It would definitely pay to check them if you've HRC'd your fueltap

It's also suprising how many floats have holes in them. I guess living in fuel 24/7 is a tough life: I wouldn't mind, but it'd be an expensive lifestyle (fuel cost) when combined with global warming (evaporation)

[NC35!]

Hi Chris,

Thanks for your reply - so basically, I need to "top and tail them". That looks simple enough.

Thanks!

[duh_ave]

If you can find someone with an ultrasonic cleaner, these work the best magic.
You only need to pull the carb bowls, floats, the tops and slides.
throw everything in with a bit of "simple green" cleaner, tap water and a cap ful of water wetter (as an antioxidant).
In a half hour to an hour, the ugliest look sparly and clean, plus no nasty chemicals and its super easy to do!

[Sligeach]

an airline is best but i have used a foot pump with a needle for pumping footballs on it to concentrate the air. works a treat.
go easy on the rubbers with the toothbrush, i just used finger to agitate the varnish