68063112 Mercruiser RING, Snap

To prevent dust from entering the fuel system, cover all openings in the injection pump, nozzle inlet connectors and injection pipes.
Removal of Fuel Injection Pump
Removal of fuel injection pump (1)
Removal of fuel injection pump (2)(1) Check the alignment marks stamped on the flange of the fuel injection pump and the pump mounting flange.(2) Remove the front cover from the engine.(3) Place alignment marked on the fuel injection pump gear and idler gear.(4) Unscrew the mounting bolts from the fuel injection pump flange, and remove the fuel injection pump together with the flange from the front plate. (a) After the fuel injection pump is removed, do not turn the engine.(b) When removing the pump gear, loosen the gear retaining nut while the pump is mounted on the engine.Disassembly, Inspection and Reassembly of Fuel System
Disassembly of Fuel Injection Nozzles
Inspection of Fuel Injection Nozzles
Inspection of fuel injection nozzle valve openingCheck each fuel injection nozzle for the following, and if defects are found, repair or replace the fuel injection nozzle.(1) Inspection of injection start pressure(a) Install each fuel injection nozzle on the nozzle tester, and move the handle up and down to release air.(b) Operate the handle of the tester at a rate of about 1 stroke per second, and read the indication on the pressure gage. The indication rises slowly, and the indicator oscillates during spraying. To obtain the injection start pressure value, read the indication when the indicator starts to oscillate.(c) If the injection start pressure deviates significantly from the standard value, disassemble the fuel injection nozzle, and make an adjustment by changing the washer thickness.
Replacement of fuel injection nozzle tip 0.1 mm [0.0039 in.] thickness of shims will change the injection pressure 0.98 Mpa (10 kgf/cm2 [142 psi]. The shims are available in 10 different thickness from 1.25 to 1.70 mm [0.0492 to 0.0669 in.] increment of 0.05 mm [0.0020 in.]
Never tap the tip of the nozzle tip when removing the nozzle tip.
(2) Inspection f fuel injection nozzle spray pattern
Inspection of spray pattern of fuel injection nozzle(a) When inspecting each fuel injection nozzle with the nozzle tester, also check the nozzle for clogs, spray pattern and leakage.(b) Make sure that the fuel is sprayed straight from the nozzle when the handle of the tester is operated at a rate of about 1 stroke per second.(3) Cleaning and replacement of faulty nozzles
Cleaning of fuel injection nozzle tip(a) Loosen the nozzle retaining nut, remove the nozzle tip, and clean the needle valve and body.
Never tap the tip of the nozzle tip when removing the nozzle tip.
(b) Use a fresh cleaning solution to clean the needle valve and body. after cleaning, assemble the needle valve and body in clean diesel fuel. The needle valve and body are precision finished. Handle them carefully, and do not change the combination of parts.(c) Tighten the nozzle retaining nut on the nozzle tip to the specified torque.(d) If the spray pattern is still not acceptable after adjustment and cleaning, replace the nozzle tip. (a) Never touch the sliding surface of the needle valve.(b) When installing a new nozzle tip, remove the seal film (synthetic resin film), and slide needle valve in the nozzle in a fresh cleaning solution to remove anti-rust oil coating thoroughly from the new nozzle.Reassembly of Fuel Injection Nozzles
Fuel Filter
Disassembly and Inspection of Fuel Filter
Installation of Fuel System
Installation of Fuel Injection Pump
Installation of fuel injection pumpCheck the alignment marks stamped on the flange of the fuel injection pump and the pump mounting flange before tightening the mounting nuts.