NC30 Carbs, what do these two pipes do?????

Forum rules
Please can you post items for sale or wanted in the correct For Sale section. Items / bikes for sale here will be removed without warning. Reasons for this are in the FAQ. Thanks
Post Reply
User avatar
28hodge
Site Supporter
Site Supporter
Posts: 650
Joined: Tue May 17, 2011 4:26 pm
Bike owned: nc30 (track) Yam YZ250 (MX)2st
Location: Kendal, Cumbria, Northwest

NC30 Carbs, what do these two pipes do?????

Post by 28hodge » Wed Nov 02, 2011 1:55 pm

Image

ok its the two pipes that are bound together by the black strip of rubber.

Are they a breather of some sort?? if so do i need to vent these to a catch tank if my bike is going to be a track bike? or should they be vented and connected to something anyway??

Any help im having a brain spasm and cant think/remeber where or how these pipes are connected.

Ta
Kurt

User avatar
28hodge
Site Supporter
Site Supporter
Posts: 650
Joined: Tue May 17, 2011 4:26 pm
Bike owned: nc30 (track) Yam YZ250 (MX)2st
Location: Kendal, Cumbria, Northwest

Re: NC30 Carbs, what do these two pipes do?????

Post by 28hodge » Wed Nov 02, 2011 2:29 pm

http://www.cmsnl.com/honda-vfr400r3-199 ... _1600.html

the two pipes i m talking about are part number 28 on this schematic

User avatar
porndoguk
Site Supporter
Site Supporter
Posts: 3293
Joined: Wed Jun 16, 2010 11:17 pm
Bike owned: NC30
Location: Middle England
Contact:

Re: NC30 Carbs, what do these two pipes do?????

Post by porndoguk » Wed Nov 02, 2011 3:03 pm

float bowl over flows arnt they, petrol pisses out of them if the float heights are set wrong
NC30 & NC23 33BHP Restrictors For Sale
£25 Inc P&P and donation to 400GB PM for more details


http://www.bikerstraining.com

Like us on Facebook for more information - First Bike on Scene - Emergency Response Skills - UK

User avatar
CMSMJ1
Moderators
Moderators
Posts: 7152
Joined: Thu May 01, 2008 9:42 am
Bike owned: NC30-No9
Location: Chesterfield, United Kingdom

Re: NC30 Carbs, what do these two pipes do?????

Post by CMSMJ1 » Wed Nov 02, 2011 3:29 pm

^^This
IMPERATOR REX ANGLORUM

The V4 is the law..

NC30 - No9 - my old mate

User avatar
28hodge
Site Supporter
Site Supporter
Posts: 650
Joined: Tue May 17, 2011 4:26 pm
Bike owned: nc30 (track) Yam YZ250 (MX)2st
Location: Kendal, Cumbria, Northwest

Re: NC30 Carbs, what do these two pipes do?????

Post by 28hodge » Wed Nov 02, 2011 3:36 pm

thought that was the case, though does this not mean that the overflow will at best pour fuel into the v of the engine, or at worst over the rear cylinders and onto the two quite possibly hot exhausts??
Or ami missing something?

So do these need to be routed to a catch tank for a race bike?

kevprojex
Site Supporter
Site Supporter
Posts: 113
Joined: Thu Jul 23, 2009 1:11 pm
Bike owned: ktm200exc gsxr400gk71b sv650
Location: Dudley West Mids
Contact:

Re: NC30 Carbs, what do these two pipes do?????

Post by kevprojex » Wed Nov 02, 2011 4:53 pm

They are float bowl vent pipes ,no petrol should come out of them, they only piss petrol out if you have a problem with the floats . i have never run them to a catch tank on my track bikes becauce nothing should come out of them if everything is ok .

User avatar
porndoguk
Site Supporter
Site Supporter
Posts: 3293
Joined: Wed Jun 16, 2010 11:17 pm
Bike owned: NC30
Location: Middle England
Contact:

Re: NC30 Carbs, what do these two pipes do?????

Post by porndoguk » Wed Nov 02, 2011 5:21 pm

Unless you have a Spill, with the carbs on the side 2 of the carbs will pee petrol out the pipes.
Last edited by porndoguk on Wed Nov 02, 2011 6:24 pm, edited 1 time in total.
NC30 & NC23 33BHP Restrictors For Sale
£25 Inc P&P and donation to 400GB PM for more details


http://www.bikerstraining.com

Like us on Facebook for more information - First Bike on Scene - Emergency Response Skills - UK

User avatar
28hodge
Site Supporter
Site Supporter
Posts: 650
Joined: Tue May 17, 2011 4:26 pm
Bike owned: nc30 (track) Yam YZ250 (MX)2st
Location: Kendal, Cumbria, Northwest

Re: NC30 Carbs, what do these two pipes do?????

Post by 28hodge » Wed Nov 02, 2011 6:01 pm

Kevprojex are they to stop the carbs getting an air lock and are really for this purpose more than a fuel vent if the floats are sticking?

kevprojex
Site Supporter
Site Supporter
Posts: 113
Joined: Thu Jul 23, 2009 1:11 pm
Bike owned: ktm200exc gsxr400gk71b sv650
Location: Dudley West Mids
Contact:

Re: NC30 Carbs, what do these two pipes do?????

Post by kevprojex » Wed Nov 02, 2011 10:03 pm

28hodge wrote:Kevprojex are they to stop the carbs getting an air lock and are really for this purpose more than a fuel vent if the floats are sticking?
all carbs have float bowl vent pipes some longer than others , they are to allow air out of the float bowl chamber as the fuel is filling the float bowl, to get fuel in the chamber you have to let the air out, if they were not vented the floats will not rise and close the fuel shut off valve and it just flood the motor , some carbs are fitted with over flow pipes as well and some carbs use the vent pipes as over flow pipes .

User avatar
28hodge
Site Supporter
Site Supporter
Posts: 650
Joined: Tue May 17, 2011 4:26 pm
Bike owned: nc30 (track) Yam YZ250 (MX)2st
Location: Kendal, Cumbria, Northwest

Re: NC30 Carbs, what do these two pipes do?????

Post by 28hodge » Thu Nov 03, 2011 12:01 pm

thanks for that

Post Reply