idiot carb question (high idle speed)

[davepoth]

Just got my car back from the garage after carb fettling, and I can now pull out of junctions without fear. Passengers have fear, but I don't.<br>
<br>
An order for new rear tyres has been made...<br>
<br>
Anyway, Although the mixture is fine, and the annoying flat spot between 1000 and 3000 has dissappeared, the idle seems to be around 1800 when the car has fully warmed up, which as you can imagine is quite annoying. <br>
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The mechanic said the choke cable is knackered and sticking, which might explain it, so I was going to pop my head under the bonnet this weekend and drop the idle down a little. <br>
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There's a whole host of information on the internet, but the one crucial thing, which way to turn the idle screws, seems to be missing. Since I don't have a carb balancer to hand, and have no money to buy one, I'd just like to know if all I need to do is turn the idle screws by equal amounts to drop the idle speed, and if so, which way I need to turn them.<br>
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Thanks very much for this. I think I'll have to have the "party dolly" at the next meet at this rate.<br>
<br>
Dave.<br>


<p></p><i>Edited by: <A HREF=http://p206.ezboard.com/bthetriumphdolo ... omiteuk</A> at: 12/10/06 3:36 pm<br></i>

[beally]

sorry this has nothing to do with your question its just the word "fettling" what exactly does this mean?<br>
my car came ( from e bay ) with the terms " the sunroof closes with some fettling". i purchased rubbing alcohol and lederhosen but misunderstood what the term meant .<br>
please enlighten me<br>
cheers confused of wanstead<!--EZCODE EMOTICON START :p --><img src=http://www.ezboard.com/intl/aenglish/im ... tongue.gif ALT=":p"><!--EZCODE EMOTICON END-->

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[Jon Tilson]

If you blip the throttle it may return to a sensible level. If it does then you just have to work out why its sticking. The rubber mounts on 1850 SU's sometimes go a bit soft and let the linkage between the carbs stick a bit. Sometimes an extra retrun spring can help. The little cotton reel bush that joins the air filter box to linkage support may aslo seem insignificant but it does help. If the choke cable is sticky and wont go back in properly you have to just change it. The choke return springs often get a bit weak and this can leave one carb with a jet that stays down a bit even with the choke in. This will mess up the mixture no end and must be fixed.<br>
The throttle stop screws do work the same ammount and its clockwise to speed up and anticlock to slow down. If you turn the screw and it makes no difference you have a sticking or leaking butterfly spindle. Rebushing is the only cure for a leak....<br>
Jonners

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[davepoth]

The butterfly on the front is a bit worn, and the carb mounts are soft. Probably one or both of those. I'll have a quick fiddle.<br>
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fettling from the old english <!--EZCODE ITALIC START--><em>fetlen</em><!--EZCODE ITALIC END-->, to make ready, basically if you have something that's essentially sound, but a bit rough, and you fiddle with it a little to make it right.

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[alun n]

With that definition it means I should fettle my women!<!--EZCODE EMOTICON START :lol --><img src=http://www.ezboard.com/intl/aenglish/im ... /laugh.gif ALT=":lol"><!--EZCODE EMOTICON END-->

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[mcharlish]

Dave, I reckon the answer to your question is simple. Firstly yes you do have to just turn them an equal amount to raise or drop the revs. Secondly just try it with one and see what happens when you turn it; you'll soon figure out which direction has what effect.<br>
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From memory I'm pretty sure clockwise will increase the revs but like I say, try it, it's that simple. Just remember how many 1/4 turns you've done so you can return it to where it was if you hit problems<br>
<br>
Mark

<p></p><i>Edited by: <A HREF=http://pub52.ezboard.com/bthetriumphdol ... harlish</A> at: 10/4/04 5:28 pm<br></i>

[BDN712V]

If it is the choke cable that is knackered, you could try a couple of things OTHER than dropping hte idle. IE, if it was set correctly at the garage, the reason for it now being high is the cable =rich mixture +butterflys open slightly. Dropping the idle on its own isn't going to sort it fully (unless I've mis-understood the problem)<br>
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Try feeding grease down the choke cable to ensure it doesn't stick as much.<br>
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Try fitting a STRONG return spring to pull it back through properly (mine's too strong - takes both hands to pull the flippin thing out!)<br>
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Remove the choke cable from its outer and check for any splayed bits of cable if it isn't solid. Remove as required ALL THE WAY BACK.<br>
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Have done this on mine with much improved results, but may well have got the wrong end of the stick with your symptoms.<br>
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Now I've got clutch cylinders to rebuild after they stuck with no drive...<br>
<!--EZCODE EMOTICON START >: --><img src=http://www.ezboard.com/intl/aenglish/im ... ns/mad.gif ALT=">:"><!--EZCODE EMOTICON END--> <br>
<br>
Tim

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[davepoth]

I managed to 'blip' the choke off by pulling it out and pushing it back in, and it settled down to about 1600. I eventually gave both carbs 1/2 turn counter clockwise, and the idle is at a much more civil 1000. The choke is still causing me a bit of grief, so that will have to be sorted, but at least I can drive the car now without shaking bits off it between 1000 and 2000.

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