The jet is the brass tube that sits in the center of the bridge, with a tapered needle poking down into it. You'll see a needle inside the jet, and the jet itself should be a few fractions of an inch down from the bridge itself. This is the part inside the carburetor, where the gas jet opens into the airstream. If you don't have them, can't find them, or have a ZS carb, you can raise the piston with a flat-bladed screwdriver pushed down the throat of the carb and twisted or levered to lift the piston. Find these they're crucial if you don't have a Colortune. When you push up on the pin, it raises the piston in the dashpot. (SU carbs only) These are little wobbly metal pins under the dashpot. ZS carbs that do allow mixture adjustment either You'll need to experiment (and I explain how) to see which way makes this richer and which way makes it leaner. Some ZS carbs do not have adjustable mixture. Later SU carburetors of the HIF type have integral float chambers, on which the mixture is adjusted by turning a screw. On early SU carbs, this is the lower of the two nuts at the very bottom of the carburetor. These set the idle speed for each carb, and are located typically behind the dashpot, near the connection of the throttle linkage. These are the things that connect the throttle linkage (the bar connected to your foot through whatever means your car uses, cables or rods) to the carburetors' throttle levers. To tune SU or ZS carbs, first locate the following components: This is a special two-part wrench that is inserted through the top of the carburetor to adjust the metering needle while preventing the air valve from rotating within the carburetor.
This costs about $20 and is simple to use. The Unisyn is the usual gauge for getting the air flow balanced between the two carbs. You will probably need to arrange to buy or borrow a Unisyn flow meter.
#Triumph tr3a auc 768 su carburetors photo high def manuals
If you would like to read more detailed information about how your SU or ZS carbs work, there are excellent Haynes manuals for each of these carburetors. The design of each is quite similar thus adjustment is performed in the same manner for either type. Either type of carb can be found on TR4s. SU carbs were used on the early Triumphs, while ZS carbs were used on the later ones. While they are interconnected, they are also independent, and need to be measured and adjusted independently. The trick to tuning Skinners Union (SU) or Zenith Stromberg (ZS) carbs is to understand that there are two things you need to get right: the air flow, and the fuel mixture. Scott Fisher, Roger Garnett, Ken Streeter,
0 kommentar(er)
