Synchronization of carburetors
Synchronization of carburetors is carried out on a warm engine and with the automatic starting device turned off.
Remove the plugs from the exhaust manifold poles and insert gauge 7062 gauges into the holes.
Connect the gas analyzer.
Remove the air filter and connect the tool 130 000. Using this tool makes it possible to ignore the increase in engine speed caused by the removal of the air filter. If the adjustment is made without using the 130,000 gauge, then it should be borne in mind that the engine idling mode after installing the air filter will decrease by about 200 rpm.
Disconnect the connecting rod, connect the carburetor synchronization device and adjusting screws 3 and 4 (see photo) amount of mixture, set the idle speed of the crankshaft with both carburetors running between 900-1000 rpm. The operation of carburetors is considered synchronized if the instrument pointer is steadily at zero.
Adjusting screws 5 and 6 quality (composition) mix to achieve carbon monoxide content (SO) in exhaust gases 2±0.5%. If necessary, use screws 3 and 4 to achieve synchronization of the carburetors at idle at a given value of CO content.
Adjust the length of the connecting rod so that after connecting it, the idle speed of the crankshaft remains the same.
If the carburetors are difficult to synchronize, check the push rod adjustment. If it is adjusted correctly, the size «A» (see photo) should be 40 mm.
Adjustment of the automatic starter
Adjustment of the automatic starter and fast idling of the engine is made with a warm engine, with the air filter removed and synchronized carburetors (see above).
With the engine off, unfasten the tie rods and raise the rear carburetor throttle control rod a few millimeters.
Manually move the choke until it opens 3 mm.
Release the throttle control rod. In this case, the cam of the starting device must rest on the second profile of the throttle control lever of the 1st chamber, which corresponds to the accelerated idling of the engine.
Without touching the throttle control rod, start the engine. The engine speed at fast idle should be 1400 rpm. If not, achieve the set value as follows:
- stop the engine and put the throttle control actuator in the full throttle position;
- adjust the engine idle speed with the adjusting screw (see photo), given that when it is turned out, the crankshaft speed decreases. One turn of the screw corresponds to a change in the crankshaft speed of about 300 rpm.
Adjust the second carburettor in the same way and connect the connecting rod.
Move both carburetors to the fast idle position with the chokes open 3 mm and start the engine without depressing the accelerator pedal. The crankshaft speed at fast idle should be 1800-2000 rpm.
Check the position of the automatic starter cover. The marks on its cover and body must match. If a cold engine is difficult to start, turn the starter cover 90°to the left (in the direction of the arrow «Rich» — «rich mixture»).
Checking the thermostat valve
Remove the thermostat valve cover. At an ambient temperature of +15°C, the valve must be open, i.e. raised above the seat. At temperatures below +15°C, turn on the ignition and after about 1 minute, the thermostat spring should raise the valve by 1-2 mm. If this does not happen, then the cause is a resistor failure and the absence of supply voltage. Check the wires and their connections.
Note. The thermostat valve seat is factory set in a climate controlled environment and must not be changed.
Checking the throttle actuator of the 2nd chamber
Remove the carburetor, disconnect the throttle actuator rod of the 2nd chamber, remove the pneumatic actuator along with the rod.
With the throttle valve of the 1st chamber fully closed, adjusting screw 1 (see photo) achieve an opening «A» throttle valve of the 2nd chamber by 0.05 mm.
Remove the cover of the pneumatic throttle valve of the 2nd chamber, check the condition of the diaphragm and replace it if necessary. Check the free length of the diaphragm spring, as well as the total length of the actuator rod, which should be 72 and 65 mm respectively.