2003 Polaris MSX 140 Personal Watercraft Service Manual, Page 40Get this manual
Maintenance Final DrivePropulsion Sacrificial Anode
The purpose of these anodes is to prevent corrosion of metal parts due to electrolysisThe mounting surfaces must be clean and the mounting bolt tight to maintain good connection between the pump and anode1Periodically inspect anode for excessive wearIf wear exceeds 50 of original size, replace anode2Check bolt to be sure it is tightIf the bolt is loose, the anode is uselessRemove anode and clean mounting surfaces on pump and anode3Apply dielectric grease to bolt threads and contact surfaces4Tighten bolt securelyZinc Anode