Changing D4 Anodes

[Simon391088]

Hi,

I plan to change the anodes in my 2 d4 engines myself (I figure that if I do it then I can keep track of how often to replace it rather than relying on someone else to tell me).

The boat is an SC35 on sterndrives (The anodes on those have already been done).
There are no seacocks to switch off the raw water.

I have a diagram showing where the 2 anodes are on each engine.

The boat is in the water.

It sounds like when I unscrew them it will start letting in water.
Is this right? Not a huge problem as I will just change them quickly.

Is there a washer or gasket on the screw which holds the anode?

It might be that the anode is actually slightly above the waterline i'm not sure.

Any advice/pointers from anyone who has done this would be welcome!

Many Thanks
Simon

 

[spannerman]

It won't let in water, some will run out from the exchanger but only 1/2 pint or so, the brass plugs can be a bit difficult to loosen so make sure you have a good quality 14mm spanner, the ones at the rear are tricky usually requiring lots of short swings on the spanner.
The ones at the front can be done easily by using a short 1/2" extension which gets you below the belt, fit the square hole over the brass plug then use an adjustable on the male end to turn it. You can use some thread sealant or PTFE tape on the threads which are tapered. You will see the zinc anode on the back of the brass plug, just screw off and replace, I use molegrips to do this.

 

[Simon391088]

PTFE tape on the threads which are tapered.

Thanks Spannerman. Won't ptfe tape insulate the anode and stop it working?

Simon

 

[GrahamHR]

Thanks Spannerman. Won't ptfe tape insulate the anode and stop it working?

Simon

No, the tape fills the gaps between the threads, the threads are still metal to metal contact.

On my D4 the boat manufacturer had fitted a 35mm2 -ve cable near the rearmost anode which made it impossbile to even get a spanner on it; relocated now to the starboard side,