i have purchased some yamaha fzs 600 carbs and am looking to fit some air filters. i am confused as to what side i need to put them on and iff i am missing any parts, I'm assuming they go on the side with the bronze coloured intakes like on a normal spi throttle, but iff some one can point me in the right direction , that would be appreciated. i am going to be getting four individual cone filters with jubilee clips.

Individual filters are inefficient, you want them all sharing one big surface area, not having a small surface area each.

The throttle needs to be fully closed or you won't have the inlet vacuum needed to pull the fuel out the carbs - bike carbs differ from other fuel systems in that they only dose the fuel that the engine literally sucks out through a straw (that's why they're efficient), the starter motor alone can't pull much air through the carbs so for any of that necessary vac at all the throttle must be totally shut.

If your starter is a bit lazy, you can hold the throttles open with your right foot, turn the engine over, and let go of the accelerator (snapping the throttles shut) whilst it's turning over. Sudden surge of inlet vac can then better pull the fuel through.

This sounds like it could be my answer! I will give it a go and let you know, what I have deduced this afternoon is that to life the needles I have to blow down some lines that are on the carbs, how can I achieve this without running some pipe to the drivers seat? :p

here we go i think

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Sorry for the influx of noob questions...

I am making no progress with my build, I am using R6 carbs, has anybody finished a conversion using these or should I just bite the bullet and replace them with cbr600 carbs?

Would ideally like to use the ones I have here just to save some chasing about. Somebody please advise

The hoses on the left and right are the ones that need to be blown in to lift the needles.

Thanks guys :-D

These two carb sets above, i'm not familiar with but it's all generally the same shizzle. All the pipework on the first ones, i dunno, looks like vac to me. Possibly the wrong source with the VW dizzy (but the late '80s Vauxhall dizzy is the other type vac) so might need blanking off.

The R6's, they've been used, i've heard of economy problems, probably just the set up in each case. Should be just as suitable.

You need to research your carbs, i bought the Haynes manual for my '99-01 CBR600F-X's (well, the bike) to help me get a full understanding before them. Details regarding tuning will differ, R6 jets will be different than ZXR jets etc but the basics like breathers, connections are the same deal.

I stand by my claims that bike carbs are relatively simple, but that's from the perspective of an experienced mechanic, working with car carbs back when they were common. The inexperienced are better off learning about carburetion first, rather than merely trying to copy instructions. As with anything.

Not aimed at anyone - i get pm's daily by various people, attitudes vary in relation to expectations. I know before i go opening my laptop to fit more ram, i'm gonna do some serious homework first, not just follow a post on a computing forum. But then, i'm no computer programmer.

I was thinking the other day as to purchasing the manual 4 the carbs I bought , and probably will do . However I want to get my car to bog bros relatively soon so wanted a quick answer on what I need to attach my air filter and what side they go on . As it looks like I'm missing some pieces , the carbs are Yamaha fazer fzs 600 1999 just for reference. I plan on paying specialists to fit and get it all running as I have spent thousands on the car and would like smooth running from the start .

You don't know which side of the carb to put the air filter on..?

On another note ..

Alot of people are running the trumpets on the carbs... What modle/cc are you using for cbr600 as the ones i've seen are single and 600's are normally a base plate/part of airbox..

Also i've seen on the net that you can get mesh to go over the trumpets ( cant remember name but illl find a pic late )

Anyone know where to get them ?

Edit.. Found these http://www.webcon.co.uk/shop/shopexd.asp?id=43

IF anyone's got any idea's on how to make a set or find some abit cheaper let me know :)

Edited 12 September, 201214 yr by jamiedub

I did say earlier I think it is the side with the bronze intakes , but need a definitive answer as I want to buy the correct size air intakes ect , as one side has 50 mm an the other 35 mm, don't want to be sending out back , and need to know iff I need pieces between the carbs an the filters

Ideally if using a filter/airbox it should cover the trunpets and the brass air jets etc so they're under the same condition

Obviously not otherwise I wouldn't have said it lol. They're open to atmosphere still. They're an OEM trumpet retaining device

no no bud sry, i was replying to mike saying you dont know what side to put the air intake on lol. I've just been reading up on carbs more an looking for images, and i think the air filters go on the larger ports with the black shutters. my carbs are pictured above, yamaha 600 fazers, I'm calling bog bros tomoz to get all info ect and i am sending them off to be jetted ect and manifold made, my inlet manifold gasket came yesterday. I've decided to definatley go for 4 seperate cone intakes as a think they look alot better than a piper cross, even though mike said he feels the air intake should be flat covering all four ports, i doubt it matters a great deal as some people say have that, some say have none, some make an air box ect ect

I heard my car loves bumblebees.

Quick question, its probably covered in here somewhere, but on my ZXR400's they have CVK stamped into them everywhere, is that a model type?

Yeah, they're Kehin CVK carbs..

Constant velocity Kehins lol

Well done jamie :-)

Oppose to what then? Flat sides?

This is why this thread is so big ....... No air filter is really stupid , I have spent thousands on my car and do not corners , air filters are essential for the safety of the engine and carbs . Just seems really pikey to not have a filter or mesh of some kind .

i personally dont see the problem. its a personal choice tbh.

my carbs are right at the back of my engine bay, pointing up towards the bonnet.

what are the odds of something getting in there? fuck all!

Think how dirty an engine bay gets, manufactures don't use air filters for banter.

I've been using bike carbs on a daily all year round, over 60,000 miles during the last seven years, and never ran an air filter.

I originally made a cold air feed but never ran it. I later made a small box/tray with a metal mesh gauze over it, but it wouldn't stay on and lasted less than a week.

Just sayin'

Iv ran two different filter setups and now run none and have done for a few thousand miles now.

Because race car

FAO Max, however useful to others.

This is a spare set of carbs where the air jet is blanked. This takes away the air supply to the emulsion tube which makes it a lot richer (it made mine over 40 main jet sizes richer)

These can be soldered up with silver solder.

Done a light tidy up back to page 24, reduced thread by 3 pages.

Thanks Steve, good idea.

Worth adding, for me my AFR was a lot more stable under wide open throttle with the air jets blanked, which was ideal.

It does however cut the air supply to the emulsion tubes, meaning fuel atomisation is reduced, and you may not get as good efficiency/economy/emissions.

In race/performance applications the holes in emulsion tubes/air supplies are often blanked/soldered up.

I went from 165 main jets, to 125 with the air jets blanked and was still richer after than with the 165's with them open.

Edited 9 October, 201213 yr by harris.racing

Gonna see how mine reacts before and after.

Its worth adding that emulsion tubes only really have any influence on light and part/half throttle, when receiving a metred amountof air as standard.