2. Unscrew the screws and remove the distributor runner.
3. Remove the support plate (photo).
4.3. Removing the Metal Backing Plate
Pic. 4.3. Ignition distributor Hitachi D4R83, D4R85 and D4R87 - models with carburetor
4. Mark the position of the pulser, remove the roll pin and remove the pulser from the shaft.
5. Unscrew the two screws and remove the stator and magnet.
6. Unscrew the wiring harness support screw on the distributor body (photo). Disconnect the harness.
4.6. Distributor Wiring Harness and Retainer Screw
7. Unscrew the two screws and remove the integrated ignition unit. Remove the gaskets.
8. Where installed, remove the screw securing the vacuum regulator rod to the support plate.
9. Remove the three screws and lift the support plate assembly while disconnecting the vacuum regulator control arm.
10. Mark the position of the coupling on the cotton wool.
11. Push out the roll pin and remove the coupling and thrust washer.
12. Remove the shaft from the housing, noting the position of the thrust washers.
13. Remove the screw and vacuum regulator, noting the location of the ground clamp.
14. Mark the position of the slider axle relative to the secondary shaft, then remove the upper E-bracket, remove the axle, weights and adjuster springs.
15. Clean and check all components, replace worn or damaged ones.
16. Carefully wipe the distributor cap and check for cracks or burnt black lines from the high voltage contact of the spark plugs. Replace the cover if any damage is found.
17. Check that the resistance between any two terminals is at least 50 MΩ (Pic. 4.4). Check the length of the brushes, replace them if necessary.
Pic. 4.4. Checking the insulation of the breaker-distributor cover
18. Assembly is carried out in reverse order.
19. Lubricate the turning points of the regulator weight, regulator spring, and rotor axis. support plate assembly, vacuum regulator linkage and support plate bearing working surface.
20. When installing the regulator weights, install the small springs first, then the large ones (Pic. 4.5).
Pic. 4.5. Installing the Regulator Weight Springs
21. Place the rotor axis on the driven shaft as shown in Fig. 4.6.
Pic. 4.6. Correct location of the runner axis on the distributor driven shaft
22. Place the base plate, aligning it with the marks (Pic. 4.7).
Pic. 4.7. Aligning the distributor support plate marks
23. When installing the pulser on the rotor axis, place the roll pin as shown in Fig. 4.8.
Pic. 4.8. Correct placement of the cylindrical pin in the pulser
24. Install the distributor onto the vehicle.
25. If necessary, rotate the engine until the two opposing lugs on the impeller are aligned with the two stator blades.
26. Using a feeler gauge, check that the air gap between the protrusions and blades is within the specified tolerance (Pic. 4.9).
Pic. 4.9. Checking the air gap of the impulsator/stator
27. If adjustment is necessary, loosen the two stator screws, move the stator, retighten the screws.
28. Install the support plate, distributor runner and distributor cover, check the ignition timing setting.