The K-151 carburetor, widespread on UAZ vehicles, is quite reliable and requires minimal maintenance associated with flushing, cleaning and adjusting. When carrying out the process of adjusting the device, remember that incorrect actions can cause a malfunction of the K-151. Carburetor adjustment is carried out without removing it from the engine.
It is necessary
- - a set of spanners and open-end wrenches;
- - rubber bulb;
- - vernier caliper;
- - pliers;
- - screwdriver;
Instructions
Step 1
To adjust the float mechanism, remove the carburetor cover. Use a rubber bulb to remove about 25% of the fuel in the float chamber. Then set the engine crankshaft to a position that does not interfere with the operation of the fuel pump and start manually pumping gasoline, observing an increase in its level in the chamber. Stop pumping when this level stabilizes. Measure the depth of the float chamber with a vernier caliper. It should be 21.5 mm (ideally) or 19-23 mm (non-critical level). To increase the fuel level with a screwdriver, bend up the float tab. To decrease the fuel level, bend it down while holding the float with your other hand. After folding the tab, re-check the fuel level in the float chamber. Combine the adjustment with the next cleaning and rinsing of the carburetor.
Step 2
To adjust the performance of the accelerator pump, remove the carburetor from the engine. Fill it with fuel and place it over the funnel with a beaker. Open the throttle valves fully and keep them open for 3-5 seconds, then close for 1-2 seconds. Repeat this operation 10 times in a row. The amount of fuel collected in the beaker should approximately correspond to the recommendations specified in the technical specifications of the carburetor. Adjust the performance of the accelerating pump by turning the adjusting needle on the drainage channel. Unscrew to decrease performance, screw to increase performance.
Step 3
Adjust the starting system without removing the carburetor from the engine. To do this, open the throttle valve a little, turn it all the way and fix the trigger control lever with a wire or rubber band. Release the throttle valve and measure the gap between the edge and the wall of the mixing chamber. It should be 1.5-1.8 mm. If necessary, adjust the clearance by unscrewing the locknut and rotating the flat head screw on the throttle lever. Change its position each time at least half a turn. When final tightening the locknut, the plane of the screw head must be perpendicular to the plane of the cam.
Step 4
Measure the gap between the levers on the choke axle. With the starting system control lever turned all the way and the air damper fully open, it should be 0.2-0.8 mm. On older carburetors, adjust the clearance by rotating the threaded head of the starting control rod. On more modern carburetors, adjust the clearance by rotating the pad securing screw on the trigger cam and moving it up or down, then tighten the screw.
Step 5
Adjust the clearance at the lower edge of the air damper with a vacuum in the cavity of the diaphragm mechanism and with the trigger rod fully retracted. To do this, having fixed the control lever of the starting system in the described way, press on the L-shaped rod of the diaphragm from above, simulating a vacuum. The gap between the edge of the air damper and the wall of the air throat should be 5-7 mm. To correct it, unscrew the screw securing the half of the two-armed trigger lever at the top of the carburetor cover. After changing the position of the air damper with the lever, tighten this screw and check the clearance again.
Step 6
Remove the air filter, start the engine and warm it up to operating temperature. Slightly pressing down on the gas pedal, fully pull out the choke control. Use a screwdriver to open the choke until it stops and make sure that the engine is running at 2500-2700 rpm. To adjust the RPM, unscrew the locknut on the primary throttle lever adjuster stop screw. To increase the speed of the crankshaft, unscrew this screw, to lower it, tighten it. After completing the adjustment, tighten the lock nut. In addition, this adjustment can be made without turning the adjusting stop screw. To do this, carefully bend the throttle lever itself with suitable pliers.
