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HenryDorsetCase
2nd July 2007, 10:17
Hi all

I know this will make me sound stupid (and cheap....) but here we go.

To get my NC30 raceday legal it appears I have to have a catch bottle. battery is sealed so no problem. Radiator has no overflow, so, again no problem.

I do have to have a catch bottle for the breathers from the carbs (one per two carbs, so two in total, and from the valve thing on the top of the fuel tank.

Fantastic. I thought I better use fuel line because it might be petrol and petrol vapour coming out... except fuel line is $8 per foot or $25/m !.

so the question: can I just use something else (clear plastic 8mm ID tubing from payless for instance)... or can I buy fuel line cheaper somewhere.?

suggestions appreciated.

Also, presumably the bottle has to be at a low point: but where do i put it? anyone else who has an NC30 please let me know.

last question, is there a size it has to be? I have a 200mm bottle I can use... is that big enough?

THanks in advance....

FROSTY
2nd July 2007, 10:49
Dude not bein a smartass here but ya got it wrong.
You'll find ttheres a breather coming off your radiator filler/overflow tank.
You also need to have your crankcase breather going into a catch bottle.
You'll find the crankcase vents into the airbox then theres a little tube coming out of a low pointon the airbox.
What I did was get some clear petrol resistant tubing from Blackwood/paykels. Catch tank wise Ive seen coke cans used at one extreme and hand crafted tanks mde as the othern extreme.
On my ZXR400 I had a 1.0l lawnmower fuel tand in the tailpiece On the SV i'm using a radiator overflow tank strapped to the front rairing brace.

HenryDorsetCase
2nd July 2007, 11:01
cheers for the response..... I am happy to defer to anyone with more knowledge than me.

my radiator does have a spot where an overflow tube should go but its blanked off. sealed somehow. no overflow tank. (maybe thats why I keep blowing holes in it?....)

I will trundle off round the engineer supply places.

Thanks again

limbimtimwim
2nd July 2007, 11:06
If the NC30 has a similar airbox to the NC35, it doesn't vent the crankcase breathers (Two from memory..?) into the airbox. It has it's own sub-airfilter, which funnily enough is attached to the airbox!

FROSTY
2nd July 2007, 11:22
Yea mate--thats to suck the oil out of the air before pumping it into the airbox--but it will still pump into the airbox eventually
What i did with my SV which had almost the same system was to unplug the tubes from the "subairbox"and run them into a T joint --Then run a tube directly into the catch bottle.Make sure you use a big enough hose otherwise the crankcases can pressurise.
PS-typing with one hand-is friggin hard yakker

more_fasterer
2nd July 2007, 15:17
cheers for the response..... I am happy to defer to anyone with more knowledge than me.

my radiator does have a spot where an overflow tube should go but its blanked off. sealed somehow. no overflow tank. (maybe thats why I keep blowing holes in it?....)

I will trundle off round the engineer supply places.

Thanks again

That would most likely be why... what about that rad that I sent down to ya? That thing's overflow still works

sAsLEX
2nd July 2007, 17:24
If the NC30 has a similar airbox to the NC35, it doesn't vent the crankcase breathers (Two from memory..?) into the airbox. It has it's own sub-airfilter, which funnily enough is attached to the airbox!

yeah thats meant to stop oil pooling in the bottom of the Air box, but it doesn't work, it just filters the hot slightly oily air on its was in to the airbox

HenryDorsetCase
2nd July 2007, 18:01
That would most likely be why... what about that rad that I sent down to ya? That thing's overflow still works
yup, thats Plan B. (well, plan A really.... but I havent gotten around to doing anything with it yet. still sitting on the bench.

I have got nice braided steel brake lines up front now: cooling system/breathers is next on the list: I get to flush it all out and put some of the grossly expensive non glycol stuff in that I bought.

I'm quite enjoying all this to be honest.... seriously.

more_fasterer
3rd July 2007, 17:23
Good stuff! The airbox that I bought (along with many other random bits) doesn't have the crankcase breather connecting to it at all, I suspect the breather just went straight into a bottle.

Flyno
17th July 2007, 12:43
i sertainly wouldnt wont to follow you if you got no breathers. your s#%t could spill making me go down! angry and heart broken lol
get the catch bottles dude!

limbimtimwim
17th July 2007, 13:12
I'm quite enjoying all this to be honest.... seriously.I've had fun too.

I ended up with a bottle just infront of the left passenger footpeg/exhaust bracket.

There is not much room low down on these damn things is there? You have to leave room get the fairings on too.

I'm still on the lookout for a slim bottle to shove between the engine and the front left engine support that wouldn't melt. I think a metal hip-flask might work. A can of "V" was a bit wide. That would be a better place than my current engine breather.

I also thought about putting the bottle between the cylinder heads.

rwh
17th July 2007, 13:31
You also need to have your crankcase breather going into a catch bottle.
You'll find the crankcase vents into the airbox then theres a little tube coming out of a low pointon the airbox.

To clarify - you're saying the 'little tube' then goes to the catch bottle? Does that one normally go down to drain at the bottom of the bike with the rest? The only similarly located tube I remember on my VT250F was the fuel overflow ... surely the idea is that the oily air gets sucked into and burned by the engine?


On my ZXR400 I had a 1.0l lawnmower fuel tand in the tailpiece

In the tailpiece? Doesn't that make it higher than all the things it's trying to catch?

Richard

slowpoke
17th July 2007, 14:28
... surely the idea is that the oily air gets sucked into and burned by the engine?


Yes, that's the OEM idea but there are at least two problems with this:
1. Hot oily air makes less horsepower
2. You can end up with a nice pool of oil sitting in the airbox and when it goes shiny side down the oil can end up on the track

A lil' tip when fitting the bottle is to mount it upside down. That is, with the lid at the bottom and the hoses coming through the base. It makes it a lot easier when you have to empty the thing.