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

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

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

Posted: Wed Nov 02, 2011 2:29 pm
by 28hodge
http://www.cmsnl.com/honda-vfr400r3-199 ... _1600.html

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

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

Posted: Wed Nov 02, 2011 3:03 pm
by porndoguk
float bowl over flows arnt they, petrol pisses out of them if the float heights are set wrong

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

Posted: Wed Nov 02, 2011 3:29 pm
by CMSMJ1
^^This

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

Posted: Wed Nov 02, 2011 3:36 pm
by 28hodge
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?

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

Posted: Wed Nov 02, 2011 4:53 pm
by kevprojex
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 .

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

Posted: Wed Nov 02, 2011 5:21 pm
by porndoguk
Unless you have a Spill, with the carbs on the side 2 of the carbs will pee petrol out the pipes.

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

Posted: Wed Nov 02, 2011 6:01 pm
by 28hodge
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?

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

Posted: Wed Nov 02, 2011 10:03 pm
by kevprojex
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 .

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

Posted: Thu Nov 03, 2011 12:01 pm
by 28hodge
thanks for that