After years of procrastination I finally setup….

[Bill Desmarais]

a freshwater flush system for the 6BTA 370, the 5th 370 I’ve owned.

simple fresh water flush setup easily reached without engine box removal.

1.Fire up the engine let er idle with the 2″ intake open.
2. Attach garden hose, open top shutoff and turn water on full blast.
3. Shut 2″ intake to off.
4. Let engine idle for 4-5 mins with fresh water.
5. Turn off engine and fresh water flow simultaneously or best you can.
6. Disconnect garden hose, shut off top valve and OPEN 2″ main intake valve.

Important in all this is making sure the engine impeller always has a water supply…no dry running.
Raw water flow alarm helps. I’ve saved an impeller or two being notified with the raw water alarm.

I serviced the after cooler for this season. 3 yrs since the last cooler service. I noticed some mild pitting on the bottom (where the core sits in the raw water soup 24/7 ) of the after cooler core even with a heavy greasing from the last service with Alco Metalube. I noticed the same pattern of pitting on the after coolers on the last pr, of 370s I owned in the Blackfin years ago.

A good freshwater flush routine should eliminate any further pitting and of course the flush will do wonders over time wit the whole SWAC cooling system.

I’ll keep ya all posted 2-3 yrs from now when I service the cooler again.

Thanks to Tony for bugging me to fresh water flush the motor.

Topic

[donald roth]

Philip wrote:

Up to you but you really don’t even have to shut the thru hull valve. The dilution will give you 80-90% and no risk of forgetting to open the valve.

Nice job!

Phil

I never close the seacock when flushing, it also eliminates any danger of force feeding when the motor is turned off, excess water just flows back out of the seacock.
You might be able to improve fresh water flow by using a 3/4” garden hose.
Just saying, that plywood spacer under the seacock looks like trouble waiting to happen!

[Philip]

Up to you but you really don’t even have to shut the thru hull valve. The dilution will give you 80-90% and no risk of forgetting to open the valve.

Nice job!

Phil

1 user thanked author for this post.

Bill Desmarais

[Rob Schepis]

Oh that made life easy….So a couple fittings, a ball valve and some Rectorseal and you were done!

[Bill Desmarais]

add some bonding to the list too.

btw, the male boss on the 2″ elbow for winterizing has been in place for 5 years now since repower/rehab.

I’ve just been “lazy” !

[Rob Schepis]

Nice, and now you gave yourself another option come Oct when it’s time to winterize the engine…

Next on the list – replace the wire nuts in the bilge and wire in the neutral safety ☺

[Tony Athens]

’bout time!

Good job and the dividends 2-3 yrs from now will show big time..

As to brass pitting– they should have used a different alloy–Maybe C83600 like the caps are made from.. Very few Yellow brass type alloys do not do well in this application. Maybe 10++ yrs ago, the alloy they used then never did that.

Tony

[Author]

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