Merc Cruiser 8.1L Coolant change

jjs2000ss

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Jul 5, 2016
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I recently purchase a 2004 Advantage boat with 52 hours on the motor and was wondering if i should change the coolant? If so, where are the drain locations?
 

alldodge

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I recently purchase a 2004 Advantage boat with 52 hours on the motor and was wondering if i should change the coolant? If so, where are the drain locations?

Howdy

No

Drain plugs are on the sides of the motor block
 

jjs2000ss

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Jul 5, 2016
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also do not change the coolant fluid? i do not believe this coolant has ever been changed.
 

thumpar

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There is probably no need to change it but if you do there should be a plug on each side of the engine down low. Make sure if you do it to collect the coolant.
 

alldodge

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The coolant has been there for 12 years, but with only 52 hours there is really no need to change the coolant. Maybe when it gets 20 years or 350 hours then sure. You will use Dexcool at that time. There is 2 drain plugs, one on each side of the engine block. They are under the exhaust manifolds and will be item 3 in link below. The plugs are 1/4 NPT and made of brass, probably painted black

http://www.mercruiserparts.com/bam/subassembly/31825/11415/120
 
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