Mixture

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SkidMark
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Mixture

Post by SkidMark » 05 May 2009, 17:36

Sorry for the repetition but I've been searching and searching...

there was thread about mixture adjustment on the AR especially related to which way increases and decreases the mixture can anyone point me in the right direction?

Cheers

Mark
AR's rock!!!
TwinAir filter, Braided Brake Hoses, Swingarm/Shock bearings done!, Rear Shock overhauled and customised by G-Force, 14-44 Gearing, Exhaust decoked (fun with Caustic Soda!), DEP silencer.

fallenmikethebike
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Re: Mixture

Post by fallenmikethebike » 06 May 2009, 19:23

SkidMark wrote:Sorry for the repetition but I've been searching and searching...

there was thread about mixture adjustment on the AR especially related to which way increases and decreases the mixture can anyone point me in the right direction?

Cheers

Mark
Hi Mark, if it,s tick over, it was probably some old tosh i posted up :? on the ARs, although the Screw is a left hand affair, it still works in a conventional way, ie, in for faster/ out for slower, in practise, however, this screw has little, other than raising the tick over effect.
Take off the smoked plastic cover to see the mechanism working, i think due to the vacuum switches it's a horrendously complicated affair, i now also believe, that the bounding tick over is a symptom of the induced, pre- ignition, all you can do is keep the pilot circuit clean, and ease mixture screw into about 1 and 1/8 turn out, but play with it and fine tune.
They will not tick over like any of the other MKs in that steady rhythmical manner, least ways none I've clapped eye's on yet. :D
Mike
VFORCE REEDS-MUGEN HEAD AND BARREL-WHITE POWER-ALL ON MY WISH LIST!!

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Re: Mixture

Post by SkidMark » 07 May 2009, 16:36

Hi Mark, if it,s tick over, it was probably some old tosh i posted up :? on the ARs, although the Screw is a left hand affair, it still works in a conventional way, ie, in for faster/ out for slower, in practise, however, this screw has little, other than raising the tick over effect.
Take off the smoked plastic cover to see the mechanism working, i think due to the vacuum switches it's a horrendously complicated affair, i now also believe, that the bounding tick over is a symptom of the induced, pre- ignition, all you can do is keep the pilot circuit clean, and ease mixture screw into about 1 and 1/8 turn out, but play with it and fine tune.
They will not tick over like any of the other MKs in that steady rhythmical manner, least ways none I've clapped eye's on yet. :D
Mike
Hey Mike,

I think your right that the varying tickover is related to vacuum rather than anything in the carb. I just had a play with mine and actually found that increasing the idle got rid of the varying tickover. I also noted that when it was 'varying' it varied in time with the vacuum altering the carb pulley. I also adjusted my mixture to 1 1/8 of a turn out so I'll see how it goes. One thing that is messing me up abit at the moment is that I can't adjust my oil pump correctly (cable on order) so I am getting some fouling on the plug 'cos of that. One day (yeaeh right!) I will pull the vacuum system components and figure out a way of testing them.

Regards

Mark
AR's rock!!!
TwinAir filter, Braided Brake Hoses, Swingarm/Shock bearings done!, Rear Shock overhauled and customised by G-Force, 14-44 Gearing, Exhaust decoked (fun with Caustic Soda!), DEP silencer.

fallenmikethebike
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Re: Mixture

Post by fallenmikethebike » 07 May 2009, 16:59

SkidMark wrote:
Hi Mark, if it,s tick over, it was probably some old tosh i posted up :? on the ARs, although the Screw is a left hand affair, it still works in a conventional way, ie, in for faster/ out for slower, in practise, however, this screw has little, other than raising the tick over effect.
Take off the smoked plastic cover to see the mechanism working, i think due to the vacuum switches it's a horrendously complicated affair, i now also believe, that the bounding tick over is a symptom of the induced, pre- ignition, all you can do is keep the pilot circuit clean, and ease mixture screw into about 1 and 1/8 turn out, but play with it and fine tune.
They will not tick over like any of the other MKs in that steady rhythmical manner, least ways none I've clapped eye's on yet. :D
Mike
Hey Mike,

I think your right that the varying tickover is related to vacuum rather than anything in the carb. I just had a play with mine and actually found that increasing the idle got rid of the varying tickover. I also noted that when it was 'varying' it varied in time with the vacuum altering the carb pulley. I also adjusted my mixture to 1 1/8 of a turn out so I'll see how it goes. One thing that is messing me up abit at the moment is that I can't adjust my oil pump correctly (cable on order) so I am getting some fouling on the plug 'cos of that. One day (yeaeh right!) I will pull the vacuum system components and figure out a way of testing them.

Regards

Mark
Hi Mark
Without wishing too evoke the old proverb about Grannies and eggs :D , have you maybe tried leaning the needle jet, ie, raise the clip a notch, thus dropping the needle and consequently, leaning of the midrange, this is generally the culprit for a fouled plug as, most of our riding tends to be centred, around that region of throttle.
Mike
VFORCE REEDS-MUGEN HEAD AND BARREL-WHITE POWER-ALL ON MY WISH LIST!!

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Re: Mixture

Post by SkidMark » 07 May 2009, 17:27

Hi Mark
Without wishing too evoke the old proverb about Grannies and eggs :D , have you maybe tried leaning the needle jet, ie, raise the clip a notch, thus dropping the needle and consequently, leaning of the midrange, this is generally the culprit for a fouled plug as, most of our riding tends to be centred, around that region of throttle.
Mike
I will get into all that at somepoint but first I want to get evereything else that could affect the tuning of the carb working correctly first. So once I have the new throttle cable - hopefully in a couple of weeks that should cure the oil pump set up problem. Then when I am in UK in hte summer I will get a range of jets, new plug etc then start experimenting with the carb setup later in the year. Thanks for the info.

Mark
AR's rock!!!
TwinAir filter, Braided Brake Hoses, Swingarm/Shock bearings done!, Rear Shock overhauled and customised by G-Force, 14-44 Gearing, Exhaust decoked (fun with Caustic Soda!), DEP silencer.


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