Northern Lights 984K / M984 — Servicing zinc electrodes
Maintenance · heat exchanger zinc
For the Northern Lights 984K / M984, from the Northern Lights operator's manual.
Applies to: Northern Lights M984, Northern Lights 984K engine
Before you start
- Do not use thread sealant on the zinc holders.
Procedure
- Check the zinc every 200 hours; more often in warm salt water or where electrolysis is a known problem.
- Remove the zinc holder from the bottom of the exchanger to drain raw water.
- Scrape or steel brush the electrode clean; replace if more than 50% is corroded away.
- Reinstall the zinc holders with clean threads for good metal-to-metal contact; no thread sealant.
- Refill the cooling system, start the engine and check for leaks.
Tools required
- scraper or steel brush Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Northern Lights M984 →
Source: Northern Lights operator's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.