Northern Lights — Winterizing / out-of-service (SP20)
Maintenance · complete unit
From a Northern Lights owner's manual covering: 643/673, M643, M673, NL643, NL673. Check it applies to your exact model before use.
Applies to: Northern Lights M643, Northern Lights M673, Northern Lights NL643, Northern Lights NL673, Northern Lights L643 / L673 engine
Before you start
- Store the set in a dry, protected place; if stored outside, protect with a cover.
Procedure
- Marine: drain fresh water and seawater cooling systems completely; shut off seacocks before opening drain cocks.
- Marine: drain water supply lines and wet exhaust line; loosen seawater pump cover and drain pump.
- Industrial: drain and flush radiator and cooling system; leave dry or refill with antifreeze-water mixture.
- Industrial: fill the fuel tank or add biocide per manufacturer's instructions.
- Industrial: seal air cleaner inlet, exhaust opening, crankcase breather pipe and fuel tank vent with plastic bags and tape.
- Change the crankcase oil and filter.
- Loosen the alternator belt.
- Disconnect and clean battery; remove to warm storage if possible.
- Clean outside of unit and put corrosion preventative on all exposed metal surfaces.
Full service-parts list: Northern Lights M643 →, Northern Lights M673 →, Northern Lights NL643 →, Northern Lights NL673 →
Source: Northern Lights owner'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.