So you want to go fast eh?... Our Datsun Z carburetor kit comes with all the bits and pieces you need to get up and running. Installation is easy on a stock 240Z and takes less than 2 hours with a pocket of wrenches and a couple screwdrivers.
Step 1 "demolition"
Remove your old set of Hitachis' or Webers', you wont need them ever again! You have now just made a new paper weight or door stop. We have 8mm freeze plugs available to plug the coolant passages in the intake manifold if needed, or just bypass the passages. Click the “Contact Us” link if you need help with this.
step 2 "Nuts and bolts and screws"
Before installation, be sure to turn the fuel enrichment screw all the way to the right, then 4 and a half turns to the left. This will put you in a good zone to start tuning the air/fuel mixture a little later.
Loosely install the connecting rod between the carbs. Install the spacers, carburetors and reattach the fuel lines. Tighten the connecting rod hardware and hook up your choke cables and throttle linkage. Attach the vacuum advance hose to the small nipple on the forward facing port on the left carburetor. Be sure to cap the bigger brass nipples on the carburetors, unless you need additional vacuum ports.
Unscrew the top cap and fill with the included 3-in-1 oil. You may use any weight oil you choose, but we've found this works best.
Adjust your choke and throttle linkages as needed.
step 3 "It's alive!"
"Fire her up!" Adjust the throttle stop screw to your desired idle. Since the 240Z has 2 carburetors, they should be synchronized for optimum performance. Use a carb synchronizer to achieve this, simply place the tool over the bore and adjust the float to halfway in the sight glass. Measure the flow on the other carb and adjust the throttle stop screw to match your previous measurement. Go back and forth to assure the flow is even between the 2 carburetors.
Step 4 "the fun part"
Now that the engine will run and idle it's time to tune your air/fuel mixture. The pre-installed needle is perfect for street and light track applications on a stock L24. You can turn the adjustment screw to the left to "fatten up" the mixture or to the right to "lean it out", that's the easy part. This will take some trial and error for less seasoned enthusiasts, it's also a good time to inspect and adjust your ignition timing.
If you would like a more precise measurement, we recommend installing an air/fuel sensor and gauge, "science doesn't lie". This will require welding an O2 sensor bung to the exhaust system, preferably in the collector pipe. You can then fine tune the mixture to get the best performance possible, we like to run a little richer than 14:1. The tuning kit is available here.
Please feel free to experiment with other SU needles, let us know! We've found through tons of trial and error that the needles installed in our carburetor kits give the best all around performance. Happy Tuning!
On a side note, we’re also working on an affordable forced induction kit to compliment the performance of these carburetors. Stay tuned for more developments!
These carburetors don't line up with the factory air cleaner, we sell adapters for the original air cleaner in the products page.
The “Original” Round Tops are the same as the ones that came with your car and the factory air cleaner installs the same.
Support is available through the contact page.
Professional installation is preferred and proof of installation is required to maintain your warranty, we will not warranty carburetors due to incorrect installation.
Lastly, we’re here to help. Let us know if you have any questions!