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Air correctionn screws ? any info please Z1r
Posted: Sun May 01, 2016 10:23 pm
Author: phil1r
Does anyone know about this subject.

I suppose most folk have never heard of them, and I can't find any reference to them but they do exist. I was told some years back by a carb specialist about these. When removing the original air box and or exhaust, to do the job right these screws have to be changed. They sit in the rear of the carb inlet, they look like grub screws. My bike came to me 7 years ago with K & N filters on. I think the original correction screws may have been changed before I had the bike, as now the Bike runs rich, with the original air box system. Everything else has been checked, I mean EVERTHING

Posted: Mon May 02, 2016 6:15 am
Author: FER
The kits were sold by LEDAR , think it was run by Leon Moss . They were not a stock part on zeds . Have you tried going down a size on pilot jets ?
fer
Posted: Mon May 02, 2016 7:05 am
Author: z1bman
the original air jets where pressed in. the LEDAR ones where screwed in so you had to drill & tap the carb
Posted: Mon May 02, 2016 7:36 am
Author: Garn 1
Funny this subject only came up recently from friend from Western Australia.
I posed the question to WiredGeorge of Carb fame .. I'll see if I can find his answer...
Easiest way is to look at this Vintage Bike forum under "Z1 Air Restriction" in Carb section...
<http://www.vintagebikeforum.org/index.php/topic,2653.0.html>
Let's know if you can't get it and I'll post up the whole forum posting.
RegardZ
Posted: Mon May 02, 2016 5:09 pm
Author: zed1015
Those Ledar air corrector jets are to remedy a lean condition caused by the increase in air flow when fitting pods or velocity stacks.
They actually richen the mixture to cure/smooth flat spots at lower revs so they aren't the solution to your rich running unless they are still fitted and you are using the air box.
Simply removing the jets (plain slotted brass grub screws) from the mouth of your carbs will put the carbs back to std in that area.
Posted: Mon May 02, 2016 11:27 pm
Author: Garn 1
Out of interest, here is a pic of a set of air correction jets complete with tap for a Gt750 Suzuki "Water Bottle".
RegardZ
Posted: Tue May 03, 2016 1:00 pm
Author: phil1r
Garn 1 wrote:Out of interest, here is a pic of a set of air correction jets complete with tap for a Gt750 Suzuki "Water Bottle".

RegardZ
Great

I knew they existed. As said before most folk don't even know they exist. Good to see some of the members have this info. They are a must for fine tuning as far as I can see.
Posted: Tue May 03, 2016 4:57 pm
Author: zed1015
You can make your own out of M5 brass grub screws or threaded bar and some micro pcb drill bits.
IIRC 0.6mm is the size for the Z but you could make several sets of different sizes to fine tune to your particular set up.
Trickiest bit is not breaking the drills.
http://www.gwr-fasteners.co.uk/m5-slott ... 1740-p.asp
Posted: Tue May 03, 2016 7:55 pm
Author: phil1r
zed1015 wrote:You can make your own out of M5 brass grub screws or threaded bar and some micro pcb drill bits.
IIRC 0.6mm is the size for the Z but you could make several sets of different sizes to fine tune to your particular set up.
Trickiest bit is not breaking the drills.
http://www.gwr-fasteners.co.uk/m5-slott ... 1740-p.asp
Mini Lathe should do it. When you say Z is it the same for the Z1r

Posted: Tue May 03, 2016 9:56 pm
Author: zed1015
phil1r wrote:zed1015 wrote:You can make your own out of M5 brass grub screws or threaded bar and some micro pcb drill bits.
IIRC 0.6mm is the size for the Z but you could make several sets of different sizes to fine tune to your particular set up.
Trickiest bit is not breaking the drills.
http://www.gwr-fasteners.co.uk/m5-slott ... 1740-p.asp
Mini Lathe should do it. When you say Z is it the same for the Z1r

Yes!
Most of the air restrictor kits like these that Ledar did were a one size fits all simple type of solution for a particular model or range.
They were designed to reduce the most noticeable fueling glitch that could be felt when fitting open pipes and carbs.
Something your average spotty tinkering speedfreak could fit with out getting too complicated with jet needles etc and really screwing up the carburation.
They are simple and they work though.
Posted: Wed May 04, 2016 6:18 am
Author: Pigford
Yes, #0.6mm is apparently correct, but I think thought that was for VM33 smoothies?
I have a set of 4 x #0.6mm air jets if someone needs some 
Posted: Wed May 04, 2016 8:45 am
Author: zed1015
Pigford wrote:Yes, #0.6mm is apparently correct, but I think thought that was for VM33 smoothies?
I have a set of 4 x #0.6mm air jets if someone needs some 
Most of them were pretty much 0.6mm ish for the big fours.
Here's a link to a 5 year old thread where we discussed this same subject and includes my explanation on what they do.
http://www.z1ownersclub.co.uk/forum/vie ... sc&start=0
Why do I have the feeling my life is just going round in circles

Air correctionn screws ? any info please Z1r
Posted: Wed May 04, 2016 10:15 pm
Author: phil1r
So if the aftermarket kit size is 0.6 for when you fit K & N's

what size was the factory stock standard one's

This would be handy to know, as if you have not owned the bike from new, who knows what bodging has gone on

Posted: Thu May 05, 2016 7:55 am
Author: zed1015
The size of the original drilling is approx 1.55mm (1.6mm bit won't go in and 1.5mm bit slides in loose) and is the same in both the 26mm and 28mm carbs but there's no reason why someone would drill it out larger as it's a brass insert pressed into the air bleed and sits quite far back from the mouth of the carb.
The Ledar jets don't replace this insert as it's now part of the carb they just restrict it by fitting upstream of it.
Posted: Thu May 19, 2016 1:20 pm
Author: Gus
zed1015 wrote:You can make your own out of M5 brass grub screws or threaded bar and some micro pcb drill bits.
IIRC 0.6mm is the size for the Z but you could make several sets of different sizes to fine tune to your particular set up.
Trickiest bit is not breaking the drills.
http://www.gwr-fasteners.co.uk/m5-slott ... 1740-p.asp
Could you tell me what sort of length the restrictor should be as I'm going to try and make some?
Cheers
Gus