Can't find 34 ADF main jets (dumb question)

[stuartrubin]

I have been suspicious that my Chinese 34ADF carb may not have the correct jets (and other tunable parts) for my engine, so I thought I would start by systematically identifying each of them and reading the values. I know I'm going to sound like an idiot, but I cannot find the main jets!

Going by this drawing https://www.carburettorshop.com/drawing ... rawing.jpg, and this https://www.dellortoshop.com/contents/e ... 73801.html, there should be two "8"'s.

I think I am looking for two brass-colored screw-heads facing the front of the car, but I just don't see them anywhere. (I have located the two idle jets and air correctors.)

Can anyone please steer me to where these parts are hiding? (This is why I did not become surgeon.... Where was that spleen? It looks a lot like the liver, I think...)

Thank you!

[stuartrubin]

I knew it was a dumb question! I could not see them because they are inside the carburetor body. The others are accessible from the outside, but not the main jet. Nevermind...

[manoa matt]

They are at the bottom of the float bowl. You have to remove the screws and remove the top cover.

[SteinOnkel]

Yeah, the stock Chinesium 34ADF jetting is questionable. Just pull them out and put in your old 32ADF jets.

I think I had to go 2 sizes up on the idle jet, though.

[stuartrubin]

SteinOnkel, the problem is that the carb I replaced was a complete "frankencarb" that was never quite right, and the ones on the Chinese one are not marked. So, I just bit the bullet and ordered news one of a known good (hopefully) size.

Thanks

[SteinOnkel]

SteinOnkel, the problem is that the carb I replaced was a complete "frankencarb" that was never quite right, and the ones on the Chinese one are not marked. So, I just bit the bullet and ordered news one of a known good (hopefully) size.

Thanks

Hi Stuart,

I have been scratching my head trying to remember the jets I put into mine.

I think 60 idle, 130 main 135 secondary, but I could be wrong.

[18Fiatsandcounting]

Steiny is pretty close. From the limited documentation that I have, here is what's listed for the stock jetting on a '75 with a 34ADFA carb: (the ADFA is identical to the ADF but with some additional emissions stuff for the US market)

Primary
idle jet: 0.50 mm (denoted as "50")
main jet: 1.25
air corrector jet: 1.85 (1.80 on the Calif. version)
Emulsion tube: F74

Secondary
idle jet: 0.60 mm (denoted as "60")
main jet: 1.40
air corrector jet: 1.70
Emulsion tube: F74

Weber carb sizes are listed in millimeters, so a 1.25 main jet has an internal diameter of 1.25 mm.

Also, the float level is shown as 6.5mm, and this is usually measured between the float gasket and the top of the float, with the carb cover upside down but with the float not depressing the ball/spring on the needle valve. Some people make this measurement with the cover held vertical so that the tang on the float just touches the ball of the needle valve but doesn't depress it.

-Bryan