On diesel generators, some parts can be installed on both the front and back sides, while others have no positioning parts. If one is not careful, it is easy to install them in reverse or wrongly. Therefore, it is specifically emphasized here that when vehicles are repaired or parts are replaced, attention should be paid.
(1) Cylinder gasket: When assembling, the side with the rolled edge should face the cylinder head. If installed in reverse, it will cause early air leakage and burn out the cylinder gasket, affecting its service life.
(2) The horseshoe-shaped groove on the top of the piston or the peach-shaped tip on the top should face upwards. If installed in reverse, it is not conducive to the mixing of fuel and air. The unburned fuel cannot generate secondary vortex movement and thus burns incompletely, resulting in the diesel engine failing to start or working abnormally after starting.
(3) Assembly of connecting rods and pistons; The oil hole at the small end of the connecting rod and the horseshoe-shaped groove at the top of the piston or the peach-shaped tip at the top should face upwards on the same side. Otherwise, it will cause the small end bushing of the connecting rod and the piston pin to be unable to lubricate, resulting in dry friction.
(4) Upper and lower tiles of the connecting rod bearing: If it is a newly replaced bearing bush, there is no distinction between upper and lower. If the bearing bush has been used, it should be reinstalled in its original position and should not be swapped up and down; otherwise, it will affect the fit between the journal and the bearing bush.
(V) Assembly of the connecting rod cover and the connecting rod: Both the large end of the connecting rod and the back of the connecting rod cover have assembly marks. When assembling, the marked parts should be on the same side. Otherwise, the original processing accuracy of the large end hole diameter of the connecting rod cannot be guaranteed, and the correct fit between the bearing and the shaft will also be disrupted.
(6) Fuel injector pressure plate: One side of the pressure plate is flat, and the other side is an arc surface. When installing, the arc surface should face the fuel injector body to ensure that the fuel injector is centered and not skewed when compressed. Otherwise, it is easy for the installation seat hole to leak air outward.
(7) Oil seals: All oil seals, such as crankshaft oil seals and starting shaft oil seals, should have the side with self-tightening springs facing the interior of the engine block. If installed in reverse, the crankcase will not be sealed tightly, causing the engine oil to leak.
(8) Plunger sleeve in the fuel injection pump: The crescent-shaped hole of the plunger should be on the same side as the positioning screw hole of the plunger sleeve on the pump casing to ensure that the end of the positioning screw is screwed into the crescent-shaped groove, preventing the plunger from rotating. If installed in reverse (i.e., rotated 180 degrees), it is possible that the positioning screw will block the oil return hole, causing the oil supply to lose control and leading to runaway.
For more questions about the generator set, please call the Beidou Power team. More than ten years of professional production and sales of power generation equipment experience, more professional engineer team to serve you, choose Beidou power is to choose rest assured, welcome on-site factory inspection.
Post time: Jul-28-2025