Clean lower unit removed from Mercury 500 50hp serial number 4965784. Passed vacuum , fluid was clean. Would always recommend a new impeller as seasonal maintenance. This is the long shaft 20” unit.

Part numbers 1643-6038A18 1643-6038A 7

At Marine Parts Exchange, we focus on repurposing used outboard engine parts. When buying from us, keep in mind that parts may exhibit typical signs of wear, but this does not affect their performance. We stand by the functionality of our parts unless indicated otherwise in the listing.

We accept returns on non-functional items, except those specifically sold as parts only. It's crucial for buyers to confirm the compatibility of the part with their engine prior to purchase. The fitment information we provide is a general guideline and may not be precise for every engine. We are not liable for fitment issues. Please check fitment before ordering, we DO NOT ACCEPT RETURNS for fitment issues. If you are unsure of fitment please message with serial and model number and we will confirm. The images shown are representative and might not be the exact part you receive, but they will be a close match. If returning an eligible item, it must be in its original condition, or a restocking fee will apply.