tuning US ZS carbs...dam things.

[JamesH]

so, i sit here smack-dab in the middle of the south US with my '80 TR7 with its standard ZS carbs. i am pretty sure that the car had a vacuum leak somewhere between the carbs and the manifold, so i stripped all that off and replaced all the paper gaskets and the rubber spacers. now it doesn't run right. big surprise. i have the (Moss) special tool, allen wrench in the middle with the clylinder around to hold....but i can't get the center bit to turn, as hard as i twist, the outside bit eventually slips. so, is there a trick i am missing? my SU carbs on my MG are this hard--i speak to it softly in an English accent and turn the adjustment screws, how do i adjust these dam ZS? thanks.

[HDRider]

The adjustment should always be able to turn anti-clockwise as that is how the needle is removed for replacement. Turning it clock-wise can bring the needle all the way up where it will jam against the adjustment screw.

If it is jammed you can remove the top of the carb and take the piston assembly out so that you can get a better grasp on it. The special tool is designed to not allow tension to be transferred to the diaphragm so once yo have the piston in your hand you can use any correctly sized allen wrench.

There is a small recessed set screw near the bottom of the piston the fits into a groove in the needle that stops it from falling out if you over adjust it. It should not effect making adjustments but you can always loosen it a bit to be sure that it has not jammed the needle into the piston.

Edward Hamer
Petaluma CA