? Chemical to clean water passages

[rodbolt17]

why wait?
as soon as your pour it down the housing its gonna drain out the ex.
kinda pointless.
outboard cooling systems are self draining.

[Tucker]

why wait?
as soon as your pour it down the housing its gonna drain out the ex.
kinda pointless.
outboard cooling systems are self draining.

Exactly, that's why you don't have to winterize outboards. I've never been fortunate enough to own a new boat. I can usually only afford to be the second or third owner of something that's lived in salt water for 10 or more years. Soon as I buy something I perform the 100hr service and flush the motor. What has worked for me is running the motor for 15-minute intervals in a tub with Salt Away and decarbing at the same time.

[Toulla]

Thank you Rodbolt! You saved me from wasting time and money trying to clean the cooling passages on a 1998 F25 motor. Should I try circulating a mixture of some sort of a cleaner through the flushing attachment? If the t-stat is removed does water from the flushing attachment circulate through the block or just the lower unit? I need to unclog this motor and I can use all the help I can get. Water pump and t- stat are new, mechanic says cooling passages blocked, he wants to do a rear- down and cleaning. I am hoping to fix the problem without the tear down. Thanks for your help.

[rodbolt17]

best way?
remove the head and ex covers and clean it.
I have seen 10 gallons of vinegar in 30 gallons of water tried.
results were negligable

[Toulla]

Thanks Rodbolt,
forger the vinegar,it's only good to clean uncured epoxy off your hands. Does water from the flushing port, not from the lower unit intake, circulate through the block, if the t- stat is removed? Excuse my ignorance, le the cooling passage diagram I was able to find is not clear.

[rodbolt17]

personal experience from about 30 years in the salt pond.
take it apart do it right and roll on.

[Toulla]

Nuff said Rodbolt. Will do it right and boat on!
Thanks.

[Manwel Grech]

How about Radiator coolant to prevent corrosion?