stern drives...

[pelican]

Originally Posted by Blue_Heron

Pelican,
Thanks for the informative post. I've got a couple questions you might be able to answer.

Mercruiser has had some problems with electrolytic corrosion, particularly on the Bravo drives, haven't they? What caused the problem? Has the Mercathode system fixed it?

I'll be using the Bravo 1 drive that came with my 25 along with a shiny new 350 Mag MPI. This is my first sterndrive boat, and I want to get familiar with the potential problems so I can do appropriate preventive maintenance. Any info experienced sterndrive owners can provide is appreciated.
Dave

that was the older bravo III drives - not an "electrolysis" problem - galvanic corrosion - electrolysis,that's hair removal...
problem came from the prop shaft carrier,too much stainless steel...
since been corrected...
you need to be carefull with those older bravo drives/transom plates - the water transfer hose - there's a bushing,it will become restricted,from salt intrusion,end result is a low water/distrurbed water flow

[Blue_Heron]

Originally Posted by pelican

that was the older bravo III drives - not an "electrolysis" problem - galvanic corrosion - electrolysis,that's hair removal...

Galvanic corrosion, right. Maybe that's why my hair is getting thinner, I have an electrolysis problem.

Originally Posted by pelican

you need to be carefull with those older bravo drives/transom plates - the water transfer hose - there's a bushing,it will become restricted,from salt intrusion,end result is a low water/distrurbed water flow

I'm setting up my Bravo with a 1.25" through hull water pickup and a strainer. That's how it was when I got it, but I'm junking the brass ball valve and using a bronze seacock. The water pickup in the transom plate is blocked off. Does that solve the problem?

Dave

[oldfielder]

You may want to tap something like this into your RW line so you can run the boat off fresh water when the need arises.http://www.yachtsofstuff.com/userPos...xs=mtg#install

[pelican]

Originally Posted by oldfielder

You may want to tap something like this into your RW line so you can run the boat off fresh water when the need arises.http://www.yachtsofstuff.com/userPos...xs=mtg#install

this is gonna sound really strange: just work with me...

flushing - sounds like a really good idea,right ?

in just about 20yrs,in this biz - i've never seen an engine failure,directly caused by an engine being raw water cooled.i've never seen a "clogged cooling jacket",never seen a block rusted through...

if the engine's filled with water - even sea water - there's an absense of air - no oxygen,right ?


the weak link on gas engines is the exhaust system - be it either stern drive,or inboard - these are the most common cause of an engine failure - some engine mfg's do not include the mainfolds in their fresh water cooling systems - some do - crusader,is a mfg that does...with all that,the risers,or,the manifolds are expelling sea water - meaning,these have a finite life.the normal accepted life is approx 5 years.flushing with fresh water will not prolong this - against popular belief...

it seems we're on this subject,so - i'm gonna run with this...

see next entry,for more info...

[pelican]

Originally Posted by Blue_Heron

Galvanic corrosion, right. Maybe that's why my hair is getting thinner, I have an electrolysis problem.




I'm setting up my Bravo with a 1.25" through hull water pickup and a strainer. That's how it was when I got it, but I'm junking the brass ball valve and using a bronze seacock. The water pickup in the transom plate is blocked off. Does that solve the problem?

Dave

running a thru hull - that avoids that potential problem...good move !