You will need
- - crank (curve starter);
- - metal brush;
- - the wrench;
- - feeler gauge blade.
Before the adjustment, wait until the motor cools. Open the hood, find the distributor (breaker-allocator) and remove the cover. To find the distributor wire going to the spark plug of the first cylinder. The first cylinder is the one closest to the radiator. Visually note the position of the runner rail, in which power is supplied to the candle of the first cylinder. When viewed from above this situation will be "ten hours."
Remove the valve cover, incidentally removing all attachments located on it. Inspect the crankshaft pulley, and locate it 2 or 3 installation risks. Often they are hidden under a layer of dirt and rust, so clean the pulleys with a wire brush. Rotating hand-crank the crankshaft clockwise, align the last mark with a label the pins on the cylinder block. Note that while cranking the engine behind the belts and pulleys you can knock the ignition control.
If after following the previous steps runner distributor is visually noted previously place, then the piston of the first cylinder came up to TDC position. Valve must be closed and can be adjusted. Try to wiggle the rocker arm of the valves – they should have a small gap. If the runner dispenser was at a different point, you can begin the adjustment valve of the 4th cylinder in the order 4-3-1-2. Make sure that the valve of the 4th cylinder closed shake of their yoke.
With a feeler gauge measure the clearance. To do this, pick a probe that would enter into it with minor, but tangible force. The required clearance value is 0.35 mm. For its correction it is necessary to loosen the lock nut of the adjusting bolt and rotate the bolt to set the desired value. Tighten the nut in stages, constantly monitoring the size of the gap with a feeler gauge. This is necessary due to the fact that when tightening this nut, the gap tends to decrease.
Using described algorithm of actions, install a thermal gap on all cylinders. The required gaps – 0,30-0,35 for the second and third cylinders, and 0.35-0.40 for the first and fourth cylinders. If the ambient air temperature at the time of adjustment of the clearances is +5 degrees and below, set the gap at 0.05 mm above the desired value. Remember that adjusting one cylinder, rotate the crank a crankshaft of the engine 180 degrees. At the end refit the distributor cap, start the engine and verify that it works.
Advice 2: How to adjust valve on a 402 engine
In order to compensate for thermal expansion valves, an engine design that provides clearance between end of valve stem and camshaft lobe. If this gap is higher than normal, the valve will not fully open if below normal – the valve is fully closed.
You will need
- - set of automotive tool;
- - bladed feeler gauges;
- - ratchet wrench crankshaft.
The adjustment of thermal backlashes between the rocker arms and valves spending on a cold engine ZMZ-402. While retaining nuts to the cylinder head and stands the rocker arm shaft should be tightened with the necessary force. Remove the air filter housing and carburetor. Disconnect the outlet pipe of the crankcase gases. Disconnect the pipeline of a vacuum regulator of the gauge-allocator of ignition.
Remove the cap from the valve rocker arms (the cover of the head unit) by unscrewing the 6 screws of its fastening. The piston of the first cylinder set at top dead centre (TDC) of compression stroke. To do this, rotate the crankshaft until the third mark until its pulley aligns with the pointer on the gear cover. The rotation of the crankshaft of spending by special key installed on his ratchet.
Make sure that the intake and exhaust valves in the fully closed position and the rocker valve can be turned freely. Check with a feeler gauge the clearance between the rocker arm and the valve. The clearance for all intake valves must be 0,4-0,45 mm. the clearance for the exhaust valves of the first and fourth cylinder shall be 0,35-0,4 mm, for the second and third cylinders of 0.4-0.45 mm. With normal clearance the probe should enter into the gap with little resistance.
If the value of the thermal gap requires adjustment, loosen the locknut on the adjustment screw with a suitable wrench. A second key hold the adjusting screw against unintentional turning. Gap adjust the slow rotation of the adjusting screw with simultaneous continuous control of the magnitude of the gap. After finishing the adjustment, tighten the adjusting screw lock nut. Again hold the key against accidental displacement. Re-check the gap. In the same way, adjust the clearance of the other valve of the first cylinder.
Rotate the engine 180 degrees and adjust the valve clearances on the first cylinder using the above steps. Then rotate the crankshaft another 180 degrees and adjust the clearances of the valves of the fourth cylinder. Then again rotate the crankshaft 180 degrees and adjust the valve clearance of the third cylinder.