Northern Lights 984K / M984 — Cleaning the heat exchanger
Maintenance
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
- Be sure to open the sea-cock after working on the cooling system and starting the engine.
Procedure
- Clean the heat exchanger core once a year or after 2400 hours of operation; close the sea-cock.
- Drain the expansion tank and heat exchanger.
- Remove the heat exchanger end covers.
- Clean the inside of the core tubes using a metal rod; flush and inspect, cleaning again if necessary.
- Reassemble, fill the cooling system, start the engine and check for leaks.
Tools required
- metal rod 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.