Winterizing Twin Cobra's

[estame6]

Twin OMC 5.0 w/ Cobra in a 1993 285 Four Winns.
I have drained the blocks and as always remove the thermostat housing, I normally pour A/F down and watch for it to show at the lower fittings. I've always noticed the A/F shows nearly immediately and at full strength on both sides. Would I be correct in assuming that there was no water present in the block to start with?

Regards,

Dave

 

[flashback]

Well sure, if the block is drained then AF will show up, water out and AF in!

Don't forget manifolds..

 

[estame6]

Ah! Begs by next question, so why the A/F?

 

[Scott Danforth]

Ah! Begs by next question, so why the A/F?

because it makes people feel good. seriously, AF is optional per the manual

 

[Lou C]

The great debate
1)Some drain & leave it dry
2)Some drain & fill with AF to reduce corrosion of raw cast iron exposed to air
I do mine as in # 2
Manual drain poke drains to make sure it really drains. Disconnect bottom end of J hose up front & let drain. Put gasket sealer on threads of drain plugs & replace. Re connect bottom end of J hose and disconnect top end of same hose. Then put a funnel in it & fill with AF till it spurts out of the neck of the stat housing. Re-connect top end of that hose. Drain & fill manifolds the same way with AF, fill via feed hoses to manifolds. Reconnect those hoses. Then put outdrive down & disconnect raw water intake hose at the stat housing. Hold it down to drain in the bilge then hold it up & fill with AF till it runs out the water intakes on the drive. This pushes any residual water out of the P/S cooler & hoses between it & transom mount & impeller housing in the drive.
There are 3 drain plugs on the pivot housing that should be removed & poked too. I get nothing from the 2 on the starboard side but the one on the port side will drain water. Actually makes sense to do that before filling the raw water intake hose with AF. Helps get the last bit of water out.

 

[Lou C]

The way I look at it….raw cast iron & steel rust VERY fast in damp climates. I spray the leaf springs on the trailer with corrosion x several times a year; my springs never rust to bits like so many do here. So I fill the engine & manifolds. Still running the original short block & intake manifold used 20+ years in salt water. So does it help? I think so. I’ll see how the BARR manifolds look when I take em off at the end of next season to inspect them (5-7 years in salt) will replace elbows as a matter of course.

 

[estame6]

Thanks Lou. I just drained the manifolds and the water didn't look too bad. I poured a little a/f till it runs out and tighten everything up. I'm in fresh water and don't worry about manifolds as much as blocks. Thanks for your input...

 

[Lou C]

here's what my old OMC one piece Batwings from the V6 looked like after 5.5 seasons in salt water