In a nutshell, winterisation should protect your engine, its controls and electrics from damp, corrosion and damage from frost or the effects of petrol ‘varnish’.
Winterising your outboard makes sure that there is no longer any threat from water left in the cooling system that might freeze and cause damage, not to mention control systems, cables and linkages.
Where applicable, to stop condensation in fuel tanks, they should be filled as high as practically possible. The fuel needs to be treated with a stabiliser to keep the fuel fresh and stop corrosion and gum forming.
Where marine batteries are present, they are more expensive than the usual car batteries because of their capacity to be deep-discharged without sustaining damage. However, they are not immune to damage from incorrect storage. They need to be kept charged to prevent them freezing or degenerating whilst not in use. One of the most common springtime issues we have to deal with is the wholesale replacement of outboard batteries that have been left flat over the entire winter, and as a result have suffered internal damage to the point that they will no longer hold enough charge to start the engine.
NWS Marine offer a uniquely bespoke outboard winterisation service, so we will only service exactly what you require, and only charge for that and nothing else. Contact us for a free no-obligation estimate.