NC30 Carby removal?

[ls1vzssz]

I attempted to take my carbies off the other day but gave up and put it all back together.
I got as far as undoing the rear intakes and then got stumped as to how to get to the front
intakes. Is this all that holds the carbies on? 4x intakes, choke & throttle cable. The front
hose intakes are basically behind the frame and I have no idea on how to get to them, let
alone re-assembly.

[Cammo]

Yes, that's all that hold the carbs in. They sometimes require quite a bit of force to take them off (especially if they've been on a long time), I usually use a piece of wood and pry them off using the rocker cover as the pivot.

You need to use a long narrow phillips head screwdriver to undo the clamps, a torch is also useful also to start with. You should be able to get to the front carb clamps in gaps of the frame/engine.

When you have them off, there are several things to do:

- Record the main jet size somewhere (front carb and back carb are usually different sizes)
- Replace main jets if you're rejetting (which most standard bikes need if you have any engine/exhaust mods)
- You can raise the needle by using an extra 0.5mm washer (standard uses 1 x 0.5mm washer), this improves midrange performance
- Enlargen the slide hole to improve throttle slide response (can't remember exact recommended size, ask on here!)
- Check all jets for blocking/clogging. You need to see daylight through all pilot jets and emulsion tubes
- Synch them if needed, always a good idea to check them - there's an easy method to use when they're off the bike. If unsure, when the carbs are off ask how in this thread

None of this is difficult by any means. Most of it is very easy! There is a noticeable improvement in rideability (and performance) after doing all this.

Just tried to find a link to Viper's great DIY guide on ye olde forum, but no luck.

Are you rejetting the carbs? In my experience it's wise to make sure the float bowls go back on the same carbs they came off (only take 1 carb apart at a time!! ), if you put the different float bowls on they can sometimes leak because the surfaces/gaskets don't mate up properly. I use a gasket goo sealant on the float bowls to make sure any leaks don't develop. Or buy new float bowl gasket rubbers, (expensive in Oz - I'm a tight ar$e!).

Final tip: Don't leave the carbs off too long (over a week), the intake rubbers can harden and contract very easily, making it impossible to get the carbs back on. You will add 5+ years of easily serviceable carbs if you buy new rubbers, but maybe an unnecessary expense if you only plan to take them off ever couple of years.


It's a bit of a learning curve taking the carbs off and putting them back on, but it gets very easy to do after a few goes. I put it off for a year or more when I got my first nc30, I kick myself for not doing it now that I know how simple it is. Give it a crack!


If there's any interest I can post up a DIY guide with pics later in the week when I get back from being away for work. Carby removal, inspect, rejet, performance mods, install etc. (It would also motivate me to clean my race bike carbs which hasn't been done since last track day... ).

[banoffee]

the float bowl rubber gasket rings are quite reasonable from Rick O, did mine when rejetting.

[CRM]

yeah go on cam, send it to me too and i will PDF it for future reference and will be added like loads others to a permanent archive linked from the facelift forum next year

[Cammo]

No worries mate, will do later in the week.

[ls1vzssz]

Do you undo the front carb intakes both from the left hand side of the frame or is there a small
access point on the right hand side which I am missing?

I can see the front left hand side intake clamps from the left hand side of the bike. I am trying to
find the front right hand side intake clamps. Looking from the right hand side all I can see is the frame? lol.

[CRM]

as your sat on the bike, i undo / do both the fronts from the left hand side (exhaust side) once the mid panels removed it makes it much easier.

also another tip. goto maplin and buy a 2' long philips screwdriver. grippy posidrive head and 2 foot long, makes carb screws a doddle.