Date: 07-12-19  Time: 21:23 PM

Author Topic: Last job is to balance the carbs, and I can't seem to get it right  (Read 3900 times)

redmandan

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I posted a topic 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%]
[/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.

tommyardin

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #1 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

unfazed

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #2 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

BBROWN1664

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #3 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.
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redmandan

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #4 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.

redmandan

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #5 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.

BBROWN1664

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #6 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.
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tommyardin

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #7 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

tommyardin

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #8 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

daviee

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #9 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   

unfazed

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #10 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

daviee

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #11 on: 08 November 2017, 07:04:25 PM »
their is a calibration adjustement screw on them no need to take them apart

tommyardin

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #12 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

Disorderlypunk

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #13 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)

daviee

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #14 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 

unfazed

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #15 on: 09 November 2017, 08:25:20 PM »
Looks like experience will have to bow to your superior knowledge  :eek :rolleyes

tommyardin

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #16 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.

daviee

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #17 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       

BBROWN1664

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #18 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
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unfazed

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #19 on: 10 November 2017, 07:44:29 PM »
 :agree

daviee

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #20 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

BBROWN1664

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #21 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.
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daviee

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #22 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
 

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #23 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.

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Re: Last job is to balance the carbs, and I can't seem to get it right
« Reply #24 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
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