NC30 Carb help

[Atrosityy]

Hi there, looking for help with my NC30 carbs. After having running issues beginning with hesitation at speed and becoming rough idle running I deemed to be caused by a fuelling issue, I've removed my carbs to inspect them. What I found is what looks to be chemical metal holding the air pipes into the carbs on the T-piece connector, which began to crumble when i removed the carbs. Finding this I'm confident this is my issue allowing air to be drawn in. I'm wondering if anyone has photos of their carbs just so I can see how they are supposed to be assembled, so I can work out what needs to be ordered to rectify it. I'm hoping they havnt been chemical metalled in because of damage to the actual metal of the carbs. These photos are to show you what i'm dealing with, I'm no bike mechanic but this just doesnt look factory to me

http://imgur.com/a/n2TQq

[calal]

Greetings from Central California, where I just happen to have the tank and air cleaner off my NC30. The two parallell 1/2" hoses are your "sub air cleaner joint pipe hoses" according to my Haynes manual, where the photos are tiny.
The black stuff in your photos appears to be what's left of the rubber joints that connect metal pipes between the carbs, or maybe someone replaced the rubber parts with some kind of goo. Your photo shows the connection to the rear carbs - there's the same connection with the other hose to the front carbs. These pipes are supposed to be open to the atmosphere through the little sub air cleaner at the rear of the air filter housing. If that black stuff is blocking the passage, the bike won't run right. If these rubber connectors are unavailable, they might be made up from rubber hose. Better have a look at the front carbs connection as well. Replacing these pieces should require separating the carbs. Your parts supplier should understand what you mean by "joint pipe" and not turn you in to the authorities.
Best of luck
Alan

[calal]

All that said, it's the "I'm no bike mechanic" part that would worry me...

[Atrosityy]

Thanks very much for the reply, I really appreciate it. I've got a parts list now in the making and looking at the parts fiche it looks like little rubber/plastic connectors that sandwich the T-joint between the carbs. It looks like a "chemical metal" substance that has been applied along with ptfe tape. I've managed to get most of it off now. I think that it's caused the carbs to draw in too much air as it had started to break up. I'm going to order the parts I need and see how it all fits when they arrive but from what I can work out (correct me If I'm wrong) the T-piece and little connection rubbers/plastics are only held together by the force of the carbs, as in there is no hose clamp? I say "I'm no bike mechanic" but I'm actually a car mechanic, but carbs arnt taught anymore and theres nobody in my work that knows about them now. It's a dying skill.

[lukemillar]

Yep - no hose clamps. TBH those rubber pieces have corroded and fallen apart on pretty much every set of NC30 carbs I have seen. Since I have removed the airbox on my racebike, those hoses now don't go anywhere so I just have the little plastic T-joints loose in the carbs without rubbers and have had no issues.

[calal]

The carbs can't draw in too much air through these hoses - these are just vents that maintain atmospheric pressure on one side of the slide diaphragm as it rises and falls. All the plumbing is there to filter the incoming air through the sub filter and prevent dirt from entering. This air is not part of the fuel/air mixture, and would only affect running if these lines were blocked, or if you had run without a filter on them for a long time, and the slide/diaphragm system had become dirty. Your running problem may lie elsewhere and I think a thorough inspection/cleaning is in order.

There are good books on the subject and I usually find good information online and often find it more quickly on youtube than by searching forums. (no reflection on this forum) This guy has a good series:

https://www.youtube.com/watch?v=ChNRzfxRidk