VM Pilot Fuel Screws - Best Notch Setting

[LeonAlistar]

Hi All,

Just finished rebuilding the airbox, carbs, replacing intake boot o-rings, adjusting points/static timing, and setting valve clearances. About to tune & sync the carbs.
Bike is a 1979 GS750 with stock VM26SS carbs, stock air box, and stock mufflers. I am at 636 ft above sea level (fairly low elevation).
Before I get started tuning, I would like my pilot fuel screws to be as close as possible to accurate as it may be some time before I can get to doing plug readings. Per the VM rebuild manual by Paul, if unknown, default adjustment should be ~1 turn. I tried counting turns but values were all over the place and I believe PO messed around with adjusting them. What I do have to reference, though, are the factory notches in the aluminum next to the screws. My thought was to select the setting that lined up with the notch and was closest to 1, but I'm not sure about the results. Below are the two values on either side of 1 turn out that would align with the notch in the carb - the value in bold is what I adjusted to - what do you think I should adjust to? Thank you in advance for your feedback here!

Fuel screw adjustment (turns out)
Carb 1: 5/8 or 1-1/8
Carb 2: (aligns at 1 turn)
Carb 3: 3/4 or 1-1/4
Carb 4: 3/4 or 1-1/4

 

[Nessism]

Forget the notches. Very lightly seat the screw, then back it out 3/4 - 7/8 of one turn. If you bottom the screw too tight, the tip will break off in the carb body. You've been warned.

 

[unfocused]

If you mean the front screw (next to the carb mount boot) than yes, start at 3/4 turn out and pretty much forget about it.
The rear one, I run about 1.5 turns out. Still tweaking this as the engine starts to seat from the recent freshning up - complete top end.
Not sure when the front screw was used because I have a set of '75 KZ900 - VM26's that don't have the front mixture screw.

I have a 77 GS750 bored to a 844. However, I also have a Dyna ignition and 3 ohm coils, 4 into1 modified, factory air box heavily modified.
However, this doesn't affect idle mixture much, I only need a little more and I've corrected most of this through pilot jet size. I'm running close to 16/16.5 - wire size drill bits

Correct me if I'm wrong but I refer to these as:
Rear - air metering screw - circle
front - fuel mixture metering screw - arrow pointing to the area of the float bowl this is hidden in.

​​

 

[unfocused]

From a set of VM24's showing the front screw.
These are from a 77 GS550
Also, can anyone decipher the markings on the float bowl?

 

[LeonAlistar]

Also, can anyone decipher the markings on the float bowl?

From what I can see, looks like maybe 30 ?

 

[LeonAlistar]

Thanks for the advice. Looks like I'll be pulling the carbs, or at least the air box, to get to them & adjust - tried adjusting by shoving my hand in there with a flathead bit and I can't reliably tell how many turns out from seated I'm at. Oh well, that's what I get for overthinking it lol

 

[Big T]

From a set of VM24's showing the front screw.
These are from a 77 GS550
Also, can anyone decipher the markings on the float bowl?

That's the pilot fuel screw
the one on the side is the pilot air screw