Adjusting mixture
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- 998 Cooper
- Posts: 263
- Joined: Mon Jun 20, 2011 10:25 pm
- Location: dumfries
Adjusting mixture
Could anyone please tell me how to set the mixture on a 1991 cooper last of the carb type,I removed the tamper proof plug but it doesn't seem to have a slotted screw in there thanks in advance
- rich@minispares.com
- 1275 Cooper S
- Posts: 6806
- Joined: Thu Aug 08, 2013 3:16 pm
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Re: Adjusting mixture
It should have the screw, but you need a very wide fat blade to turn it as they can be mega tight, they also chew the slot up in the screw really easy.
Don't forget that it's opposite to the early carbs, so its in to rich, out to weak
Don't forget that it's opposite to the early carbs, so its in to rich, out to weak
- mini63
- 1275 Cooper S
- Posts: 939
- Joined: Tue Mar 26, 2013 2:24 am
- Location: Adelaide, Australia
Re: Adjusting mixture
I think with HIFs you also have to run the engine at 3000rpm to cool the fuel in the bowl before setting mixture and then set the mixture within 1-2 minutes.
"You must learn, Keats, there are more things to life than breaking and entering."
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- 1275 Cooper S
- Posts: 1012
- Joined: Sat Nov 03, 2012 6:00 pm
- Location: West Sussex
Re: Adjusting mixture
I have never heard this before...mini63 wrote:I think with HIFs you also have to run the engine at 3000rpm to cool the fuel in the bowl
before setting mixture and then set the mixture within 1-2 minutes.
... but I do know that there is a bi-metalic "thingy" which is part of the self-adjustment
system for these carbs. The "cooling the fuel" fuel concept would most likely be
something to do with this.
I am fairly sure that this would not have anything to do with being able to locate and
turn the appropriate screw.
Still very valid and worth remembering as far as actual calibration goes, though!
SHAMELESS PLUG:
This needle selection utility is available on the main MK1 site...
http://mk1-performance-conversions.co.u ... l_carb.htm
Ian
- mini63
- 1275 Cooper S
- Posts: 939
- Joined: Tue Mar 26, 2013 2:24 am
- Location: Adelaide, Australia
Re: Adjusting mixture
I can recall late MGBs Ian running twin HIFs the factory steps required running the engine to cool the fuel for just that, the bi-metallic jet for temp compensation in the bowl.ianh1968 wrote:I have never heard this before...mini63 wrote:I think with HIFs you also have to run the engine at 3000rpm to cool the fuel in the bowl
before setting mixture and then set the mixture within 1-2 minutes.
... but I do know that there is a bi-metalic "thingy" which is part of the self-adjustment
system for these carbs. The "cooling the fuel" fuel concept would most likely be
something to do with this.
I am fairly sure that this would not have anything to do with being able to locate and
turn the appropriate screw.
Still very valid and worth remembering as far as actual calibration goes, though!
SHAMELESS PLUG:
This needle selection utility is available on the main MK1 site...
http://mk1-performance-conversions.co.u ... l_carb.htm
Ian
just part of the mixture setting up.
fussy things.
"You must learn, Keats, there are more things to life than breaking and entering."