105635-0350 ZEXEL 9 420 615 325 BOSCH AUTOM. ADVANCE MECHANISM 9420615325 1056350350 225002800a

Black Or Gray Engine Runs Smooth
Engine Used at an Altitude Higher Than 2500 ft. (762 m)...At altitudes higher than 2500 ft. (762 m) the rack setting must be changed on 1145, 1150, and 1160 Engines to keep the smoke at a correct level. *Engine Used in a Lug Condition..."Lugging" (when the truck is used in a gear too high for engine rpm to go up as accelerator pedal is pushed farther down, or when the truck is used in a gear where engine rpm goes down with accelerator pedal at maximum travel) the engine causes a reduction in the intake of air with full fuel delivery to the cylinders. Because there is not enough air to burn all the fuel, the fuel that is not used comes out the exhaust as black smoke. To prevent lugging the engine, use a gear where engine can have acceleration under load.Dirty Air Cleaner...If the air cleaner has a restriction indicator, see if the red piston is in view. If there is no restriction indicator, restriction can be checked with a water manometer or a vacuum gauge (which measures in inches of water). Make the connection to the engine side of the air cleaner or to the engine inlet manifold. Check with the engine running a high idle rpm. Maximum restriction is 25 in. (635 mm) of water. If a gauge is not available, visually check the air cleaner element for dirt. If the element is dirty, clean the element or install a new element.Air Inlet Piping Damage or Restriction... Make a visual inspection of the air inlet system and check for damage to piping, rags in the inlet piping, or damage to the rain cap or the cap pushed too far on the inlet pipe. If no damage is seen, check inlet restriction and replace clean air cleaner element.Exhaust System Restriction...Make a visual inspection of the exhaust system. Check for damage to piping or for a defective muffler. If no damage is found, check the system by removing the exhaust pipes from the exhaust manifolds. With the exhaust pipes removed, start and run the engine to see if the problem is corrected.Fuel Injection Timing Not Correct. *Rack Setting Too High. *Low Quality Fuel...Test the engine with fuel according to recommendations. See FUEL SPECIFICATIONS.Valve Adjustment Not Correct or Valve Leakage...Check and make necessary adjustments. Intake valve adjustment is .015 in. (0,38 mm) and exhaust valve adjustment is .025 in. (0,64 mm). Valve leakage normally causes the engine to "misfire" (ignition not regular) and run rough. Valve leakage can be checked using the cylinder leakage tester. *Defective Fuel Nozzles...Defective fuel nozzles will normally cause the engine to "misfire" (ignition not regular) and run rough, but can cause too much smoke with engine still running smooth. Remove the fuel nozzles and test.Engine Runs Rough
Misfiring Cylinders...See the topic MISFIRING AND RUNNING ROUGH.Fuel Injection Timing Not Correct. *Automatic Timing Advance Does Not Operate Correctly...Engine must have smooth acceleration. A timing advance that does not operate correctly