105931-3731 ZEXEL 9 420 614 211 BOSCH GOVERNOR 9420614211 1059313731

Recommended Procedure
1. Air in Fuel System ... With air in the fuel system the engine will normally be difficult to start, run rough and release a large amount of white smoke. To remove the air from the fuel system, open the manual bleed valve on the fuel injection pump housing. Operate the priming pump until the flow of fuel from the manual bleed valve is free of air. Close the manual bleed valve and fasten the fuel priming pump. Start the engine. If the engine still does not run smooth or releases a large amount of white smoke, loosen the fuel line nuts one at a time at the cylinder heads, and permit the fuel to come out until it is free of air. Tighten the fuel line nuts. If air is not removed in this way, put 35 kPa (5 psi) of air pressure to the fuel tank.
Do not use more than 55 kPa (8 psi) of air pressure in the fuel tank or damage to the tank may result.
Check for leaks at the connections between the fuel tank and the fuel transfer pump. If leaks are found, tighten the connections or replace the lines. If there are no visual leaks, remove the fuel supply line from the tank and connect it to an outside fuel supply. If this corrects the problem, the suction line (standpipe) inside the fuel tank has a leak.2. Valve Adjustment Not Correct ... Check and make necessary adjustments as per Testing and Adjusting Section of this Service Manual. Intake valve clearance is 0.38 mm (.015 in) and exhaust valve clearance is 0.64 mm (.025 in). Also check for a bent or broken push rod.3. Fuel Injection Timing Not Correct ... Check and make necessary adjustments as per Testing and Adjusting Section of this Service Manual.4. Automatic Timing Advance Does Not Operate Correctly ... Check with engine warm. Use the 8T5300 Timing Indicator Group to check the automatic timing advance unit. Check to see that the advance is smooth and that the amount of advance is correct. See Fuel System of the Testing and Adjusting section of this Service Manual for the subject Checking Engine Timing And Automatic Timing Advance Unit With 8T5300 Timing Indicator Group. If the timing indicator is not available, make rapid "acceleration" (increase in speed) from low idle to high idle. Engine must have smooth acceleration.A timing advance that does not operate correctly can cause delays of the engine acceleration at some rpm before high idle, or possibly cause the engine to run rough and have exhaust noise (backfire) during acceleration. This condition is difficult to find if engine acceleration is slow or at a constant engine rpm.5. Bad Fuel Nozzle(s) ... Find a bad nozzle by running engine at the rpm where it runs rough. Loosen the fuel line nut at the cylinder head enough to stop fuel supply to that cylinder. Each cylinder must be checked this way. If a cylinder is found where loosening of