650 f2 "extra" jets question should they be there

[warren3200gt]

Guys, cleaning up a set of what are allegedly F2 carbs which has 15 size pilots and 107.5 mains. In addition they have what look like genuine "extra" jets in the pilot air inlet. They don't have any size or identification numbers on them. The inlet they are screwed into is threaded as is the "jet". So Im thinking that maybe they should be there but i've never come across these on any mikuni carbs Ive worked on previously or on any showing on google search pictures.
Some one please explain! Its the brass jets in the left hand pilot air intake.

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And from the side.


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[Z1parR]

LEDAR or similar air corrector kit perhaps ?

[z1bman]

LEDAR or similar air corrector kit perhaps ?

&1 they don't look standard if they was they would have a number stamped on them

[warren3200gt]

So if they are not supposed to be there, which was my first thought until I saw they are nicley threaded, whats the point? Why not just put different pilot jets in to richen the pilot cicuit.

[z1bman]

they are fitted to counteract problems that occur when fitting pods or K&N filters if you have a standard exhaust & stock air cleaner you will need to remove them

[warren3200gt]

Bike is running stacks and piper 4 into 1. Going up 2 on pilots from std and ditto on mains. Ditching the extras. Hopefully should get me in the "adjustment"range.

[8 Valve Mark]

I've got the same fitted (on 3 out of 4) no numbers,on cv34 carbs,pod filters N 4 into1 Harris that came with my 79 z1000 un-ltd. carbs are mint and only have a single cable capability, weird eh? does anyone have a spare wee jet as mentioned above ?? or even swap good non CV carbs for mine? mark call/txt 07510-529545

[zed1015]

Ledar/Freeman automotive air corrector jets (usually 0.6mm orifice)
Leave them in if using pod/stacks no matter what jet sizes you use elsewhere.
They help clean up the flat spot off idle when going from pilot to jet needle and main jet by richening the mix in the emulsion tube to compensate for the extra air flow through the venturi.
Just fitting bigger pilots and mains won't fully smooth out the fuelling throughout the range.
This is what the corrector jets are for.

[warren3200gt]

Even with them in it'll still need bigger pilots though right? That's the bit I dont understand. Std on a 650 is 15 pilots and 102.5 mains. It has 15's and 107.5 in it plus these "adjuster". So am assuming the carbs came from a bike that had either or both pods and 4/1. just adding the bigger mains and "adjusters" leaving the pilot as std wouldn't be sufficient would it?

[zed1015]

The corrector jets help richen up the whole range from pilot with a much lesser effect towards the main.
Don't assume you need bigger pilots just because you fits stacks and a pipe.
99% of the time you can leave the pilots alone.
Fitting bigger pilots only masks the off idle fueling glitch and over richens the starting circuit.
These air correctors fill in the bit that fitting bigger pilots try to compensate for and in some circumstances you can actually reduce pilot jet size with these correctors fitted.
My tuned café with 1075 wisecos, Norris cams, stacks, bored out carbs etc runs stock pilots with the corrector jets fitted and the fueling is near perfect.

[chrisNI]

Count yourself lucky to have these if you were looking for them I don't think anyone makes them any more. Ledar are long gone since the chap was killed in a car accident as I recall someone will fill in his name...

[GPZ592]

Leon Moss was the guy running LeDAR. The bloke was a genius with carburation. I had one of his kits on a GPZ600R with Ramair filters & Motad pipe and it pulled clean as you like with no flat spots.

IIRC he was killed when a horse box trailer broke loose from it's towing vehicle and rammed into his car

Mark.

[KWACKERZ1]

Proper english eccentric he was.

Very very clever and a pioneer of dyno's in this country, he used a water paddle type dyno to load up the roller.
Only place i have ever been dynoed where he measured the amount of fuel flow going in as well as all the usuals stuff like exhaust mixture etc.

Real nice bloke, who called a spade a spade.!