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SU tapered needle... Newbie...

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Donzi

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Howdy folks, just got my first LBC, a '75 Midget. love it. The PO had twin HS2's installed and I am trying to get the carbs set right. Is there a good starting place to set the tapered needle in the piston? When I removed the carbs, the needles were at different heights. I can't seem to find much information on this aspect of adjusting them.

thanks
 
Donzi: The shank (thicker round upper part) of both needles should be flush with the brass needle guide and with the bottom of the piston. Mixture for each carb is then adjusted by varying the height of the jet.
 
PS; Donzi do you have a good workshop manual? You can get a Haynes Manual for MGB at Autozone, but I am not sure about one for the Midget. Or try your public library and photo copy the bits you need. The information on tuning in the MGB is generally the same, so you can you that as a guide in a pinch.
 
Yes, I have a Haynes manual that came with the car and I've also searched the internet on the subject. It seems like there's everything else mentioned except the placement of the needle.
 
Hello Donzi,

As stated earlier the shoulder should be flush with the face of the piston. The other basic setting is that the jet is screwed two full turns down from when it is flush with the bridge in the carburetor. So when your piston is out and you can see the jet, screw it up until it is flush with the bridge then turn it down two full turns.
You should not need to adjust the jet very much from there. If you find that the mixture is way out when running then your needle is the wrong one.

Alec
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