Skinner's Union (SU) Carb Remanufacturing Service 

#1  SU Remanufacturer in the world for Datsun "SU" carbs

Also offering  Reman service for Volvo B18/B20 (HS 6)

Please go to the Master Price list for pricing 

The below is general info about the carb remanufacturing process.


  SU carbs are completely stripped to bare aluminum, cleaned, inspected, blasted to remove all stains, acid stripped, and machine polished.  Domes and pistons are "dashpot drop-tested and matched".  The drop test ensures that the pistons go up at  the same rate, equalizing the flow of air/gasoline to your engine.

   All steel linkage and hardware is acid stripped and cyanide zinc replated with the factory colored yellow/orange/purple zinc plating and baked for 5 hours.  Includes replated throttle return springs and center linkage when available.

 After the bodies are machined, the carbs get polished.  All ZTherapy carbs are machine polished with a unique high  pressure (22 G's of force) machine polish technique.  This is not a wheel polish.  These carbs shine better than when they came out of the molds.  By polishing in this way, we close the pores of the metal.  They shed dirt better, and look great!

Throttle Shafts are sized to receive double sealed stainless steel roller bearings.  Carb bodies are precision machined for shaft alignment and installation of both bearings.    This alignment process in conjunction with the bearings virtually eliminates shaft binding, vacuum leaks and idle problems for years to come.

  New Nissan or Genuine SU or ZTherapy hardware is installed.  You get new floats, new choke nozzles, clamps, new needles, gaskets, needle & seats,  gas tubes,  etc...  This ensures that your carbs will perform for another lifetime!

 Your carbs are reassembled to factory specs with great care.  All carbs are fitted with custom ZTherapy nozzles to cure the sticky choke problems inherent in SU/Hitachi carbs.  The result is a carb set that looks and performs as new.
         Shipped with a free "Just SU's" DVD to aid in installation, tuning and balancing .

  Warranty:  ZTherapy Inc extends a three year limited warranty on this service.


Cars of unknown mechanical history:  Your carbs have been fiddled with by 30 years of mechanics, some of questionable ability.  Why fight with it? Get a new set that is set up right.  Your mechanic will thank you.  Average Tuning time is 1 hour using the video.  If it takes longer than that after watching the first hour of "Just SU's", please call for tech support!

 Extra Carbs Core credits-send us your spare SU's for $200 each off (up to 3 sets + core set).    We are currently accepting 2" Jag, 240Z, 2000 Roadster and 38mm SSS carbs.  All cores must be complete with all linkage and return springs to receive full credit.  We were accepting others, but after the quarterly inventory, we found over 700 lbs of British 1 3/4" carb aluminum polished and ready to go.  This exceeds our threshold of "core cushion". No Stromberg or 1 3/4" HS6, please.


"Rebushing" Service  Remanufactured bodies--  ZTherapy RollerShafts!
 Price $490/pr  core charge $200          Datsun240Z, 2000, 1500, 1600, British/Swedish 1 3/8, 1 1/2, 1 3/4", 2"
We do not rebush carbs.  After several warranty returns in 1998, we gave up on oversized throttle shafts and line honed bushings.  If the intake was warped, it twisted the carb body and the customer complained of  "sticky shafts".  So we reinvented the wheel, dumped the bushing, and had a tiny stainless steel bearing made for us that is doubled sealed. We created the best possible lifelong seal for the throttle shaft.  The idea was to come up with a permanent fix.  This is available for all Japanese units, and all British/Swedish over 1 3/8 inch bore.  ITS Racers--identify yourself on initial call up for Custom Roller Shafts that are legal. 

Carb bodies are assembled with polished butterfly and high torque button head allen screws.
Order these first, swap out your parts one carb at a time, and return your bodies as cores for the core charge refund. 


Polish:  We took great pains to find the correct surface finish for the aluminum.  These are concourse quality carbs that are sold by  Motorsport Auto,, and other regional shops.   Our machine shop uses a  "tumbler" machine that beats the aluminum with a special media at 22 G's of force.  The result is a carb body that is highly polished inside and out.  Every nook and cranny is polished equally.  This is impossible to get with a buffing wheel or other type of polish.  It greatly increases the surface density of the aluminum, inhibiting tarnishing and corrosion.  A side benefit is  that it also polishes the inside of the dome.  This makes our job easier when we match up domes and pistons for a more consistent air flow through the carb mouth.   It also makes cleaning the carb easier! 

Plating:  We tried 9 platers in 4 states before finding the right company for this job!  ZTherapy plating has a mix of orange, purple, gold, and green tint in the plating mix.  This replicates the correct British and Japanese plate.  All steel parts are hydro blasted, sandblasted, rinsed, stripped with acid, rinsed, plated, rinsed again, then baked for 5 hours at 350 degrees.  This plating will not rub off or rust.  It also lubricates the linkage, which is essential for proper and long lasting operation without sticking.