How to clean an outboard’s lower unit [SOLVED]

It seems that an outboard’s lower unit would benefit from using Sea Foam marine as a cleaner,…but since lube volume is so small (less than a quart for my 200 Mariner), how much cleaner is needed to even be effective?

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Jim D.
Jim D.
3 years ago

Thanks for the question Jim. An outboard’s lower unit is fully-contained and sealed without exposure to the atmosphere or contaminants, so we think less about the need to run a cleaner during operation. Even so, we’re familiar with the stubborn/heavier gear lube that stays in the gear case when draining the old lube. <strong>Try this:</strong> The best time to clean lower unit crud is right after you drain the old gear oil. Once everything has drained with both plugs out, use a can of Sea Foam Spray with the straw and spray around into the top gear case hole while everything drains from the lower hole into a drain pan.