DD 671 - what do I need to watch out for ?

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

AussieCraig

Senior Member
Joined
May 16, 2013
Messages
179
Location
USA
Vessel Name
The Salty Swallow - named by wife
Vessel Make
Private builder - 50' Trawler
Gentlemen, as there is a 671 in my new/old boat, is there anything to especially watch out for ? I am aware of the need for clean fuel, air and regular oil and filter changes naturally but are there any traps for young (?) players ? Thanks again for your experience and wisdom...
 
Aussie, Make sure before you crank it that the shut off actually moves the injectors. Take the valve covers off and hit the stop button and make sure the goodies are moving. That's as far as I got. Check the damper and one great word of advice I got was to buy a co2 fire extinguisher. That is how you shut it off in case of nothing else working.
 
As a precaution many folks will carry spare "jumper struts" .

These are simply the thin tubing that connects the injector with the fuel rail.

Only a few bucks each , but if they leak diesel goes directly into the crankcase.

Usually leak after a dummy runs the rack and over tightens them.

IF you need Da Book the best one is the WWII USN training manual.

They can be had on line $30.00 to $75.00 and will explain EVERYTHING!

Also be very wary of overheating , over 210 is SHUTDOWN instantly !!!!!.

The engines are very unforgiving if ever overheated.
 
Have the serial number handy. It contains lots of good info.
 
Check the oil every time to make sure it has enough and also that its NOT TO FULL as diesel can leak directly into the crankcase. The newer lower sulfur diesel tends to damage the older gaskets. I had the fuel pump gasket leak which allowed diesel to pass directly into the crank case which thins the oil, but if high enough can cause the engine to run away. Also check to make sure the raw water is flowing. As soon as I start it I visual check if water is coming out. Also at least once a year check the raw water impellor.

If the hoses are more than 10 years old they should be check and replaced as needed. I let the 671 run for several minutes and check for fluids leaks before leaving the dock. I have my diesel mechanic check the 671 and gen set May/June each year, and change the fluids each Sept/October
 
How many hours should be between oil changes ?
 
There's special oil for 2 stroke Detroit s I think it's RPM Delo 100. Talk to FF.

The thing you'll need to watch out for most is verbal flack from non-Detroit Diesel powered boats ..... except me.

I have no idea where New Braunfels is but nobody would give you flack in Alaska. Lots and Lots of DDs in fish boats still.
 
Last edited:
There's special oil for 2 stroke Detroit s I think it's RPM Delo 100. Talk to FF.

The thing you'll need to watch out for most is verbal flack from non-Detroit Diesel powered boats ..... except me.

I have no idea where New Braunfels is but nobody would give you flack in Alaska. Lots and Lots of DDs in fish boats still.



That is what I use Delo, Diesel Engine Lubricating Oil and 40 weight. Change ever 100 to 125 hours and/or once a year which ever comes first. If there has been under 20 hours I have not changed the oil. But its best to put away/stored with clean fluids.

Oh, when stored for long periods of time make sure you at least bump to change the piston position every other month, because on a 2 stroke there is always a cylinder open. I start the engine every other month and let run for about 1 minute just to move the parts/fluids and put a new coat of oil on the cylinder walls. However if you do not start the engine make sure the intake and the exhaust are plugged to keep moisture blowing through.

I would contact a diesel mechanic in your area as to what is done in your area as you will probable need one anyway. I have my diesel machanic come each spring to check/listen/feel and bless the engine. :thumb:
 
Thankyou yet again Gents !
 
If you take good care of it-the 671 will be running the boat when they take it out to spread your ashes!
 
If you take good care of it-the 671 will be running the boat when they take it out to spread your ashes!

Now THATS what I like to hear ! Thankyou !!!:thumb:
 

Latest posts

Back
Top Bottom