The reason for the carburetor bore is the desire to increase engine power and torque, which are proportional to the rate at which the engine's cylinders are filled with an air-fuel mixture. To achieve this, squander the carburetor diffusers.
Necessary
a set of screwdrivers, a pin with a diameter of 10 and a length of 200 mm, needles
Instructions
Step 1
Remove and completely disassemble the carburetor, fix the lower part of it on the workbench, but very carefully so as not to damage it. Grind the diffusers with coarse sandpaper, while there should be no sharp edges, do not change the shape of the diffuser in any case.
Step 2
The size of the diffusers depends on the volume of the engine, since there comes a moment after which no matter how much they are bored, the effect of increasing the power will no longer be, and at low and medium speeds, the engine will simply "choke". For example, for a standard VAZ engine of 1.5 liters, the diffuser bore limit is 24 mm for the first chamber and 26 mm for the second. To measure the diameter of the diffuser, take a wooden wedge and insert it into the diffuser, then measure its thickness at the point of contact with the walls, which is clearly visible.
Step 3
After boring is finished, cut a steel pin with a diameter of 10 mm lengthwise by 4-5 mm, insert sandpaper number zero into its slot, and clamp the other end of the pin in a drill. Grind bored diffusers with this tool so that they do not have any roughness.
Step 4
Take a file and start sanding small diffusers and nozzles on the carburetor cover. Gently grind off the traces left after the casting, give their fasteners a drop shape, making the upper part smooth, which tapers downward.
Step 5
Blow out all the channels of the carburetor, as well as the manifold, then rinse all parts with water under pressure, and be sure to rinse it a second time, now with gasoline. Assemble the carburetor, while the accelerator pump jet should be from model 073, one that is output only to the first chamber. This will allow gasoline to be fed directly to the engine. Record the fuel jet numbers for each chamber prior to assembly.
Step 6
If you cannot adjust the carburetor with the screws responsible for supplying the fuel mixture and enriching it with air, go to a special stand where you can select the correct jet numbers for optimal carburetor operation.
