Fazer Owners Club - Unofficial

Bikes, Hints'n'Tips => FZS600 Fazer => Topic started by: redmandan on 06 November 2017, 11:13:26 PM

Title: Last job is to balance the carbs, and I can't seem to get it right
Post by: redmandan on 06 November 2017, 11:13:26 PM
I posted a topic (http://foc-u.co.uk/index.php/topic,23257.0.html) a few weeks ago and received some sage advice from you foccers. New fuel and air filters, carbs out and completely overhauled, checked my valve clearences, new plugs and caps, cooling system drained, flushed and re-filled. Got the bike back together, pressed the switch and she fired up again, no more carb overflow and firing on all cylinders.


The last job was to balance the carbs, partly because I have never done it before and partly because of a kind of ticking/ clanging sound at the top of the engine on the left side which gets better as the bike reaches temperature. After reading around a bit it would seem carb balancing could help. I read through pointer2null's post on the subject to prepare myself.


Here is a short vid of my carbs before I adjusted anything: [size=78%]http://www.youtube.com/watch?v=JgNX9bVLVzA (http://www.youtube.com/watch?v=JgNX9bVLVzA)[/size]


Now this is where the problems started. Rather than buying the carb tune like a sensible person I bought a cheap 4 gauge vaccuum gauge thing off amazon. To reduce needle flutter it has little plastic valves that you screw in and out on the plastic tubes connected to the carbs. The problem is that half a turn on these seems to change the readout quite significantly and I can't be sure I'm getting an accurate reading. I got 3 + 4 carbs balanced, kind of, and then I fiddled around for ages with the centre screw but all it seemed to do was increase the revs with the needles barely moving up or down.


To reduce the revs back to idle I started to also play with the idle screw. Eventually this proved futile as it seems the idle screw had no effect anymore on the revs (could it have come detached or something at the carb end?) while the revs sit at 3000 and I can't get them down anymore. I was spinning and spînning the idle screw and it had no effect. Dejected, with a wife who I had promised this would only take 20 minutes and a toddler crying for his absent father I turned off the ignition, put the cover back on and hung my head in shame as I walked back into the house.


Should have just bought the carbtune.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: tommyardin on 07 November 2017, 12:07:51 AM
Hi redmandan,
I purchased a set of gauges very similar to yours on the recommendation of some in here mine are blue in colour where yours are black but the gauges look exactly the same. About 45 quid if I remember right. It has four brass extension connecting rods, two are longer than the others, they came with four black rubber/plastic tubes and four cheap and nasty valves to go in line. First recommendation is get yourself down to your local tropical fish shop and get yourself four better quality adjustable valves. Around a quid/ quid fifty each.
Now I have never tried my gauges out as thus far my old girl runs smoothly. What I would say is check that the throttle cable is not too tight and holding the throttle open, if it is no amount of adjusting on the throttle stop screw will make any difference.


I'm sure other foccers will come back to you who have used the gauges just like the ones we have, and they will have more of an idea how to adjust your carbs up.
It's just that they are a bunch of old codgers that have to get to bed early because of the brain damage they have suffered because they are to foccing mean to buy the right sized helmet. Tight bastids.  :eek
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: unfazed on 07 November 2017, 12:17:06 AM
And the worst old codger of all is Tommy, the miserable git is so tight he wears the wifes clothes  :rolleyes because he won't buy his own  :lol

There are 3 adjuster screws, one between 1 & 2 ( left as you are sitting on the bike) second one between 2 & 3 and the third one between 3 &4.

You need to balance 1 & 2 and 3 & 4 first, then balance the pairs with the centre screw.

From your video 1 & 2 are fine, adjust the Screw between the 3 & 4 which are out of balance. Then adjust the centre one between 2 & 3 to balance both sets.

They do not need to be absolutely perfect just as close as you can get them.

When finished adjust the idle speed to about 1200 and then the TPS  :thumbup
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: BBROWN1664 on 07 November 2017, 01:09:10 AM
:agree with unfazed

but

adjust the TPS and idle speed before AND after you do the balance job.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: redmandan on 07 November 2017, 01:37:01 AM
Tommy - that reminds me, something I forgot to mention: My throttle was acting a little strange as well. I don't think I reconnected them properly after tearing down the carbs. It's almost like it isn't springing back to idle. If I manually roll the throttle forward the revs dropped right off, almost cutting the engine out. It stays like that till I blip on the revs again. I guess there is a decent section on throttle setup in the Haynes manual that I should read through.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: redmandan on 07 November 2017, 01:39:52 AM
And I have also read from some old posts that locating the plastic valves at the engine side, as opposed to 10cm off the gauges as I have them now, will help greatly in getting a more accurate reading.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: BBROWN1664 on 07 November 2017, 08:35:35 AM
you just gently turn the screws on the gauges until the dial/float/whatever stops fluctuating so much to make it easier to read. Screw it in too far and the level on the gauge will drop.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: tommyardin on 07 November 2017, 08:55:45 AM
And the worst old codger of all is Tommy, the miserable git is so tight he wears the wifes clothes  :rolleyes because he won't buy his own  :lol

There are 3 adjuster screws, one between 1 & 2 ( left as you are sitting on the bike) second one between 2 & 3 and the third one between 3 &4.

You need to balance 1 & 2 and 3 & 4 first, then balance the pairs with the centre screw.

From your video 1 & 2 are fine, adjust the Screw between the 3 & 4 which are out of balance. Then adjust the centre one between 2 & 3 to balance both sets.

They do not need to be absolutely perfect just as close as you can get them.

When finished adjust the idle speed to about 1200 and then the TPS  :thumbup
I wear them cos I like it not cos I'm tight  :eek
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: tommyardin on 07 November 2017, 09:03:59 AM
There you go red, sounds like you may have been adjusting the screws in the wrong sequence. There are sooooooo money smart arses in here that know so much about the Fazers, it's a great place to be and folk are always willing to share their knowledge. Hope you get it sorted soon, sounds like you should now be on the right track.
Well done lads :thumbup
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 07 November 2017, 06:06:07 PM
with the gauges like you have you need to calibrate them first or you will never get them spot on   
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: unfazed on 07 November 2017, 07:13:30 PM
On most gauges it is easy enough to do, remove/unscrew the glass, remove the needles and and replace them all to the same position
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 08 November 2017, 07:04:25 PM
their is a calibration adjustement screw on them no need to take them apart
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: tommyardin on 08 November 2017, 11:49:06 PM
their is a calibration adjustement screw on them no need to take them apart


Same as that, mine also have screw on each gauge to set the needles to the same parked position.
Still not used mine, had them over a year but my old girl is as steady as you like on tick over, starts first prod of the button with no choke every time, and just a touch of choke if the temperature is close to zero, not that I ride the bike then. Never checked the wotsit valve thingy on the side of the carbatooter, needle on rev counter is steady at tick over. So the old adage comes into play 'If it ain't bust don't fixit'  :lol
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Disorderlypunk on 09 November 2017, 02:03:19 AM
i think daviee is referring to the calibration of the carb balancers - i have had my eye on the same setups for a while but i know my bench setup works pretty well then i tune it with my ear and a piece of pipe (years of practice and still learning from my pops, webers and classic rally cars gives an advantage) the problem after balancing is the idle screw and getting it right from there


think of it this way - a cylinder will usually take as much air as it wants in there once ballanced (allowing same air volume) - our job is to give the right amount of fuel for that amount of air weather that be during tickover (idle screw) or jets and needles for later in the ranges
if your running stock everything then a quick balance then idle screw setup is all you need to worry about
(assuming you have clean carbs and no gummed up emulsion tubes)


a lot of people also overlook doing a compression test if things are a bit lumpy at tickover (including myself)
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 09 November 2017, 05:38:46 PM
to balance the gauges you need to connect them one by one to the same carb  and adjust them to the same reading then you can connect them to the carbs ready for balance none of this taking apart crap how is that going to get them calibrated ? and they all  park  at the needle stopper the way i have described is the only way to do it accurately 
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: unfazed on 09 November 2017, 08:25:20 PM
Looks like experience will have to bow to your superior knowledge  :eek :rolleyes
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: tommyardin on 10 November 2017, 01:30:15 AM
The way I was told to calibrate the gauges (nothing to do with the bike nor fitted to the bike) adjust the first needle Adjusting screw, but, stop a needles width from the stop pin, then do exactly the same to the other needles. If you take the needle up against the stop you can continue turning the screw but the needle cannot go any further as the pin stops it and although your calibration will look right because the needles are all against the stops but in fact they could actually be a mile out.
Some of the quad gauges do not have pins for that very reason


Now I am not a expert in fact not even a novice as I have never even fitted my gauges th the bike, all I am doing  is to say what I have been told.


Would love to hear anyone else experiences on calbration of the gauges.
What David says sort of makes sense, I think.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 10 November 2017, 06:27:27 PM
the gauges measure vacuum so the only way to calibrate them is with vacuum that is why you plug them into one carb if it reads at say 12 oclock then you set the rest to read the same on the same carb then when you plug them in to the carbs for balancing then you will get the exact same vacuum when you adjust them to read the same it is the only way to get accurate carb balancing with them cheep gauges far better of with mercury gauges they never go out of calibration       
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: BBROWN1664 on 10 November 2017, 06:50:19 PM
there is calibration and there is calibration
generally speaking, as long as all 4 start at the same reference point then when they are all reading the same when you balance the carbs you can be fairly certain that the carbs are set correctly.

If you really want to calibrate the gauges you will need to send them away to a specialist. All you do by adjusting the screw is setting the zero point
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: unfazed on 10 November 2017, 07:44:29 PM
 :agree
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 10 November 2017, 08:54:05 PM
sorry but you are wrong read the instructions that come with them it tells you how to calibrate them before use i was in the tuning trade for 10  years so have a fair idea how it works
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: BBROWN1664 on 10 November 2017, 09:12:03 PM
Daviee - all they are telling you is how to ensure they are zeroed. Calibration makes sure they read the correct value at a range of pressures from zero to max.
You are correct that you set the needle a hairs breadth away from the stop to ensure that they are all set the same. You are not calibrating them in the true sense though.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 10 November 2017, 10:05:30 PM
no you are wrong zero means nothing on cheep gauges set them all to the first carb theen they will all read the same trust me i have more  experience than you end of story
 
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Disorderlypunk on 11 November 2017, 12:26:10 AM
im with daviee on this one
if there is a stopper to say zero (1bar) then i would avoid buying them, i would prefer something that does both negative and positive pressure.
when calibrating at home i would use one carb as a control to see they are all giving the same reading (calibrated to each other)
these setups are not that good at giving correct pressure readings but they can be good for making sure they all have the same negative pressure.
if you want accurate pressure readings from 4 individual carbs then the 30 quid kits are not going to cut it.

i will say i dont have one of these relatively cheap set ups myself but have come across them now and again - they can be usefull as long as they are calibrated now and again.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: BBROWN1664 on 11 November 2017, 11:09:02 AM
these setups are not that good at giving correct pressure readings but they can be good for making sure they all have the same negative pressure.

That's my point exactly DP.

Daviee - You may have spent some time professionally or otherwise playing with vacuum gauges but as a qualified aircraft avionics engineer I do know a bit about suck and blow instruments and how they work as well as how they should be calibrated.

for information, the ones with the stop pin need adjusting to be a fraction off the pin when you use them to take the ambient atmospheric pressure into account. When the ambient pressure is lower, the needle will try to move below zero if the last time you used it, the ambient pressure was higher. Just so you know the reason :pokefun
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 11 November 2017, 02:49:54 PM
if you no so much about suck and blow you would realise inlet side only sucks thats how it creates a vacuum and if you no  so much about cheep vacuum guages then you will realise im right as you set them on a carb not to zero just off the stop needle that is not where you need them to be accurate you need them to be accurate at the vacuum reading the carb gives but of course being a motorbike mechanic and rolling road operator means nothing to balancing carbs you need to no about aircraft's to do that  :z
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Disorderlypunk on 13 November 2017, 09:13:05 AM
ok this is getting out of hand very quickly


so setting them all at the same zero would work in a perfect world and most of the time could work
HOWEVER
due to how these sort of things work they need calibrated in use as they have moving parts and springs and all other things that may not be exactly the same as each other and will show a different reading anywhere other than 1 bar


another way to explain  calbration is  2 torque wrench's sitting on a table, one calibrated, one way out
you have no way to know which is which untill you put them under force on a test rig
ok we dont have a test rig for vacuum BUT WE DO we have four different ones of them
each cylinder is its own test rig giving the same vacuum all the time (ish)

Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Jamieg285 on 13 November 2017, 02:01:24 PM
Surely the calibration technique depends on what or how you are trying to measure?

If you are measuring actual values of vacuum, then it's important to get them zeroed properly.

If however you're just trying to balance them, it doesn't matter whether the needle starts at 0 or 100, what's important is that all the guages read the same value for the same level of vacuum.

Therefore, in this argument, I side with Daviee.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Disorderlypunk on 13 November 2017, 02:19:08 PM
now is the time to take the piss
its time for a poll


https://goo.gl/oENybF (https://goo.gl/oENybF)
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: BBROWN1664 on 13 November 2017, 02:27:52 PM

Surely the calibration technique depends on what or how you are trying to measure?

If you are measuring actual values of vacuum, then it's important to get them zeroed properly.

If however you're just trying to balance them, it doesn't matter whether the needle starts at 0 or 100, what's important is that all the guages read the same value for the same level of vacuum.

Therefore, in this argument, I side with Daviee.


This is what I have been saying.


You set the gauges to all read the same to start with. DO NOT use the stop needle, set the gauges a fraction off it if you have one as that way you know all the gauge as are starting at the same point. Atmospheric pressure will try to move the gauge above or below zero so you set it every time you use it.


following that, chances are your gauges are not accurate anyway and have not been professionally calibrated so you are just looking to see that you have the same reading on all four cylinders.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 13 November 2017, 05:52:37 PM
if you are wanting to measure the actual vacuum them cheep analogue gauges like the ones pictures  are deffo not the way to do it the will get your carbs close if you calibrate them as  i have said but the best is deffo mercury gauges ,
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Hugh Mungus on 13 November 2017, 07:37:33 PM
If you're wanting to save money by doing the carb balance yourself then buy mercury gauges. They may be more expensive than the other gauges but you're already saving on labour costs at a workshop. So buy some good one's and look after them.


If you've got the cheaper dial gauges you do need to sync them together by using one carb as a bench setting for all four gauges. It is the most accurate way you're going to get a proper reading. Even with mercury gauges it is advisable to do the same to double check that each gauge is giving the same reading as it can point to leaks in the tubes etc.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: darrsi on 14 November 2017, 06:48:55 AM
Think i paid around 50 odd quid for my Morgan Carbtune gauges, in used but virtually mint condition.
After the second time of use you've technically saved money through labour costs if you were paying a mechanic, plus after the fifth time of using it you actually get a bit handy at using it, plus your learning curve increases even if it can be a slightly frustrating process with adjustment screws in hard to see daft places and twice now i've kinked my fuel tank pipe so it's run out of fuel mid process.
A very worthwhile and satisfying job once done though, the bike runs really sweet afterwards, as long as your air filter, TPS, and bike in general is in reasonably good order whilst it's being adjusted.  :)
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Hugh Mungus on 14 November 2017, 12:25:06 PM
It can turn a dog of a bike into a really sweet ride. Always worth doing.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: redmandan on 14 November 2017, 02:12:28 PM
OK guys, if I can ask some advice again. I've been having another go and I'm stumped again. Made a vid to show my problems:
http://www.youtube.com/watch?v=57CVLvmeIy8 (http://www.youtube.com/watch?v=57CVLvmeIy8)
To re-iterate the video: I have the carbs balanced about as well as I can hope/get with the vaccuum gauges I have. The idle screw is now basically redundant. The only way I can change the idle speed is by turning the centre carb balancing screw, just a quarter of a turn changes about 1000 revs and doesn't affect the balance at all. Am I doing something wrong here? Shall I just put it back together and forget about it?


Thanks for any help
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: unfazed on 14 November 2017, 04:54:37 PM
Bet your sorry you asked the first question :lol :lol :lol

Most likely the throttle cables are adjusted incorrectly

Check the adjuster at the handlebar side is backed off fully and if it is loosen the cables at the carburettor end
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: His Dudeness on 14 November 2017, 05:48:47 PM
Ohh the joys of bikes :lol Sounds like it's running on three cylinders when it's idling
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 14 November 2017, 08:05:20 PM
you have the setting miles out you need to  take the carbs off and reset all the ajusters to normal and bench sink them first you proll  have the balance adjusters screwed in to  far thats how your idle is not working unscrew them out as far as you can then set your idle adhyster to control idle speed then adjust your balance
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: redmandan on 14 November 2017, 08:29:12 PM
I'm sure you're right daviee but the reality is hard to accept. I just got it all back together, drain/re-fill the coolant again, fiddle about getting the intakes on and off again, getting the fiddly throttle cables off and reattached....

Can anyone tell me exactly how the idle screw works? I understand that the balance screws adjust the pitch of the carb flaps relative to one another. Does the idle screw adjust all flaps equally then, or does it work in another way?
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: daviee on 14 November 2017, 08:47:30 PM
basically the idle adjuster is a throttle stop where the cables turn they pully that opens all the butterflys the same the idle adjuster  stops the pully closing to far if you have all the balance adjusters screwed  to far in the will  hold the buterflys open thats why your idle adjuster is not working and if you have your throttle cable adjusted wrong it can affect it aswell that why i said you need to start from the beginning bench ballance the carbs reset the cables etc as you have prolly everything out from where it should be 
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Hugh Mungus on 14 November 2017, 09:09:04 PM
Find the basic settings (must be in a book somewhere or on internet if one of these fine folk don't know.) Set all the carbs to the same settings, adjust throttle cable and idle screw. Then start the balancing process again.
No need to take anything apart. Yet...
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Disorderlypunk on 14 November 2017, 09:18:57 PM
if i get my new jets tommorow i will have a look and if i see something i will try and do a little video of what is going on in that region
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: tommyardin on 14 November 2017, 10:36:34 PM
:agree


I'm with Stupid who is with Stupid also.
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: Disorderlypunk on 06 January 2018, 10:04:37 PM
ok so this controversial thread rears its ugly head again but on a positive note
my gran (bless her) handed me cash on the deal that i only used it on something for my garage and to enhance my side business
deal i thought so a new set of sockets and a CARBTUNE later i had some work ahead of me
first test came with all kinds of trouble and i knew i had big problems
https://youtu.be/COCTPbbPHeE (https://youtu.be/COCTPbbPHeE)
after some work i found the problem and someone either cocked up earlier in its life or the fazer has a self moving spring
https://youtu.be/Yh-vl43DTSA (https://youtu.be/Yh-vl43DTSA)
whatever balancing tool you have or are going to get, first buy some extra long screwdrivers it will make your life so much easier - mine just arrived today so i will do it again at some point as i will have better ability to adjust but things are much better now
- this is definatly a worthwile job doing because things are so much better now
Title: Re: Last job is to balance the carbs, and I can't seem to get it right
Post by: darrsi on 06 January 2018, 11:04:21 PM
ok so this controversial thread rears its ugly head again but on a positive note
my gran (bless her) handed me cash on the deal that i only used it on something for my garage and to enhance my side business
deal i thought so a new set of sockets and a CARBTUNE later i had some work ahead of me
first test came with all kinds of trouble and i knew i had big problems
https://youtu.be/COCTPbbPHeE (https://youtu.be/COCTPbbPHeE)
after some work i found the problem and someone either cocked up earlier in its life or the fazer has a self moving spring
https://youtu.be/Yh-vl43DTSA (https://youtu.be/Yh-vl43DTSA)
whatever balancing tool you have or are going to get, first buy some extra long screwdrivers it will make your life so much easier - mine just arrived today so i will do it again at some point as i will have better ability to adjust but things are much better now
- this is definatly a worthwile job doing because things are so much better now


Tip....a 3" long flat blade screwdriver works better on carbs 3 & 4