Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
The sludge trap is located on the front end of the crankshaft pin. Oil continuously flows through this passage under pressure from the oil pump. The purpose of the trap is to prevent very small particles from being pumped past the connecting rod bearings. The sludge trap can only be accessed when the crankshaft is removed from the engine. It should be cleaned whenever the crankshaft is removed. Cleaning is not a part of any
regular maintenance schedule.
The photo below shows the sludge trap half full. In reality, this means that the particles are at least partially blocking the oil holes that provide lubrication to the connecting rod bearings. In other words, the photo below shows a bad scenario in which oil cannot flow. Damage to the crank pin and half shells is the result.