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Jet centering tool


Jedi Trainee
I have a slide sticking on my TR3. I almost positive its an off center jet because when I pull the choke the slide goes down with the jet. I got in a jet centering tool last night but no instructions. Anyone used one before? I could use some advice.
Thanks /ubbthreads/images/graemlins/driving.gif


Jedi Knight
if it's the one I'm thinking about you just loosen the big nut (not the adjusting nut) that holds the whole jet assy to the bottom of the carb, put the tool in the place where the needle goes, put the dashpot back on and screw it down, and then tighten up the nut. Move the damper up and down to make sure it is still square, replace the needle, check it again and you should be in business.


Senior Member
And you SU guys say ZS's are complicated....


Darth Vader
Hello Bill,
there is no need for a special tool to centre S.U. jets.
Simply take the dashpot and piston assembly off, clean the piston and dashpot internally with solvent (no abrasives at all) and ensure the needle shoulder is flush with the piston bottom face. Screw the jet adjuster until the jet top is flush with the jet holder. Replace the piston dashpot assembly, but take out the damper rod. Slacken the jet clamp nut and push down on the piston then re-tighten the jet clamp nut. Screw the jet back down 12 flats (Two turns, which is the nominal mixture setting) and check that the piston will lift and drop cleanly, it should.

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