idle adjust screw at end of turning

[psyfi_1]

hi guys i recently did my carb balance and noticed after it got warm idle was a little off so i turn idle screw it to keep it at 1100rpm on thing is the idle screw wont turn any further will i have to turn back the screw and rebalance to its origanl setting the carb is balanced properly but it was only ticking over on 1000 -1100 rpm should i set the idle screw back to factory turns and retry balance??

[psyfi_1]

i must add i reset pilot screws to there standard 2 turns

i  didnt change the choke cable for a new one...

[Gnasher]

You first need to set the pilot screw adjustment so as to pull the correct level of Hg, this should then put your idle back to a factory setting, in your case the idle adjustment is probably set too high to compensate for a too low Hg setting at idle.  Most including stealers have no idea how to balance carbs, its not just hook up the gauges and start adjusting.  When they do it throws out the pilot idle adjustment, they compensate by adjusting the idle and this pushes it to the ends of it's adjustment, owners/stealers then start playing with the TPS and before you know it the whole lot is all over the place. 

[psyfi_1]

the first thing i did was set pilot screws they are back to original settings

they are set to two turns like the haynes states

[psyfi_1]

though i cant find anything in the haynes about how many turns the idle screw should be at factory setting

[Gnasher]

the first thing i did was set pilot screws they are back to original settings

they are set to two turns like the haynes states

That's a datum setting they need to be set so as to pull 230 - 250mmHg, that should be somewhere around 2 turns.   

[psyfi_1]

yeh thats what they are set too........................ i did it before putting the carbs back on the bike

[Gnasher]

though i cant find anything in the haynes about how many turns the idle screw should be at factory setting

There isn't a setting, you set the pilot Hg first, then balance the 1/2 and /3/4 then balance the 1-2 & 3-4 together finally you adjust the idle screw to obtain 1150 - 1250 idle.   If you can't get the Hg setting somethings wrong and you're wasting your time.

[Gnasher]

yeh thats what they are set too........................ i did it before putting the carbs back on the bike

[/size]2 turns may be too much or not enough you need the Hg measurement. [size=78%][/size][size=78%] [/size]

[psyfi_1]

this is what i did cleaned carbs out check pilot settings most where out some by 2 turns seated them and then turn out two turns got carbs back on bike set tps sensor.... then put on my gauges and balanced 1/2 then 3/4 then between 1/2 and 3/4 got them all level when blipping throttle.... but i forgot to set idle after wards so today i warm her up to running temp and adjust the idle screw on thing was it wouldnt turn any further i got it to 1000 -1100 rpm but it will not turn any further up it will only drop it down loads till it stalls

[psyfi_1]

i thought the hole point of factory setting is thats what they should work at

[Gnasher]

this is what i did cleaned carbs out check pilot settings most where out some by 2 turns seated them and then turn out two turns got carbs back on bike set tps sensor.... then put on my gauges and balanced 1/2 then 3/4 then between 1/2 and 3/4 got them all level when blipping throttle.... but i forgot to set idle after wards so today i warm her up to running temp and adjust the idle screw on thing was it wouldnt turn any further i got it to 1000 -1100 rpm but it will not turn any further up it will only drop it down loads till it stalls

Then something is wrong mate, you usually have to turn the main idle screw down not up, the butterfly's aren't open enough, which means they're not pulling enough Hg.  The 2 turns out should give you the correct air setting, from there you have to set the Hg it MUST be between 230 - 250mmHg on every carb before they're balanced the number is very important.  Then the fun starts you've got to get 1/2 balanced still pulling the Hg then 3/4 and then balance 1/2 & 3/4 still pulling the the Hg figure if you can't get them all in balance pulling the Hg figure and idling at the correct speed there's something wrong.     

[psyfi_1]

do you know what the how many turns the idle screw is at factory setting.....if so i will turn to that and adjust the pilot screws from there..... and rebalance

i cant seem to find any info in the haynes as two where the idle screw is set at factory

[Gnasher]

There isn't one, but a good starting point should be somewhere in the middle of the adjustment range. 

[psyfi_1]

just to let you now i adjust the pilot screws a quarter of a turn out and it seems to have helped i will put the carb gauges on tomorrow if its not pissing down and will check everything over thank you for your help i will post again after i have put the gauges back on and tested / balanced

[psyfi_1]

the first time i did the carb balance she sounded so much better..... and now after changeing the pilot screws shes quite and sounding alot nicer and not so jumpy on the needle lol

[Bretty]

What's a "stealer"?

[psyfi_1]

 a bastard that nicks peoples bikes....

[Hugh Mungus]

What's a "stealer"?

Dealer - as in your main motorbike showroom.

[Grib]

this is what i did cleaned carbs out check pilot settings most where out some by 2 turns seated them and then turn out two turns got carbs back on bike set tps sensor.... then put on my gauges and balanced 1/2 then 3/4 then between 1/2 and 3/4 got them all level when blipping throttle.... but i forgot to set idle after wards so today i warm her up to running temp and adjust the idle screw on thing was it wouldnt turn any further i got it to 1000 -1100 rpm but it will not turn any further up it will only drop it down loads till it stalls

Then something is wrong mate, you usually have to turn the main idle screw down not up, the butterfly's aren't open enough, which means they're not pulling enough Hg.  The 2 turns out should give you the correct air setting, from there you have to set the Hg it MUST be between 230 - 250mmHg on every carb before they're balanced the number is very important.  Then the fun starts you've got to get 1/2 balanced still pulling the Hg then 3/4 and then balance 1/2 & 3/4 still pulling the the Hg figure if you can't get them all in balance pulling the Hg figure and idling at the correct speed there's something wrong.   

I'm a bit confused by this - if I adjust the vacuum to 230-250mmHg on each carb using the pilot screws, what is left to adjust using the balance screws?

[BBROWN1664]

It may help, it may not, but the idle should be between 1150-1250. I tend to set it to 1250 as its easier to work out on the rev counter,

[Fazerider]

this is what i did cleaned carbs out check pilot settings most where out some by 2 turns seated them and then turn out two turns got carbs back on bike set tps sensor.... then put on my gauges and balanced 1/2 then 3/4 then between 1/2 and 3/4 got them all level when blipping throttle.... but i forgot to set idle after wards so today i warm her up to running temp and adjust the idle screw on thing was it wouldnt turn any further i got it to 1000 -1100 rpm but it will not turn any further up it will only drop it down loads till it stalls

Then something is wrong mate, you usually have to turn the main idle screw down not up, the butterfly's aren't open enough, which means they're not pulling enough Hg.  The 2 turns out should give you the correct air setting, from there you have to set the Hg it MUST be between 230 - 250mmHg on every carb before they're balanced the number is very important.  Then the fun starts you've got to get 1/2 balanced still pulling the Hg then 3/4 and then balance 1/2 & 3/4 still pulling the the Hg figure if you can't get them all in balance pulling the Hg figure and idling at the correct speed there's something wrong.   

I'm a bit confused by this - if I adjust the vacuum to 230-250mmHg on each carb using the pilot screws, what is left to adjust using the balance screws?

Me too.
Adjusting the pilot makes the mixture richer or leaner at very low throttle openings. I always thought the correct way to judge the setting is with a gas analysis probe in the downpipe for each cylinder (using the little port on the OE headers).
With no gas analysis equipment and aftermarket exhaust system, I’ve always set the pilot by counting turns.

[Steve3351]

Hi Foccers...WOT IS hg and how do u measure it...??!!
I'm having similar carb probs... bike is running ....but ROUGH. I went to great lengths building the home-made MANOMETER...
only to find that i couldn't get 1 & 2 into balance no matter how much I adjusted the screw...of course I unscrewed it all the way out and
had to buy a special torch (EBAY) and long reach screwdriver (LIDL) ....and had to glue the screw to the screwdriver to get it back in.
Depressing....... am thinking of upgrading (?) to fuel injection....I'm reluctant to even give this problem to the bike shop...do they know how to do it properly...do they give a FOC...?!!?

PS i also adjusted the pilot screw to two turns out...like it says in the (YAMAHA) workshop manual