Engine damage
The first place to look to see if debris has damaged the engine is to remove the clutch basket then slide the oil pump rotors out. The oil goes through the oil pump before it goes through the oil filter. If debris goes through the oil pump it will badly score the crankcases causing a drop in oil pressure. The only way is to replace the crankcases...... might as well do the whole engine with the cost of the cases & labour.
The first place to look to see if debris has damaged the engine is to remove the clutch basket then slide the oil pump rotors out. The oil goes through the oil pump before it goes through the oil filter. If debris goes through the oil pump it will badly score the crankcases causing a drop in oil pressure. The only way is to replace the crankcases...... might as well do the whole engine with the cost of the cases & labour.