Broken bolt for zinc on frame BF20D

Hi all,

More questions as I restore this 2004 BF20D.

The bolt for the zinc on the mounting frame (not the 2 on the gear case) is broken off flush with the surface and the zinc is gone (previous owner). They have a zinc bolted to the frame using one of the holes for the tilt adjusting rod. How would you remove the broken fragment? Can this be accessed from the back side? Pictures from the shop manual are attached. The bolt stays in salt water so I'd like to have full zinc protection.

Also are there any internal zincs on these engines? I did not see any listed in the shop manual.

Thanks,
Barry

This may be a case where you could benefit from using a RESCUE BIT. The Rescue Bit is designed for helping remove broken off screw extractors and drills but also works really well on broken off fasteners with more precision and control. Used with a die grinder or Dremel tool , depending on shaft size, at high speed. I find these bits to be ideal for prepping broken bolts for accurate drilling. Pricey but VERY effective.

The heat from drilling that small a fastener will usually break the bond of the threads. That is why I use left hand twist cobalt bits when drilling for extractors. Many times the fasteners will come out during drilling.

I don't think there is any access to the back side of that bolt that will make removal any easier.

There is an additional zinc inside the thermostat housing on this engine. Item 1 in link below. You will want to replace the screw too as it will probably be corroded and weakened. Item 12.

https://www.boats.net/catalog/honda/outboard-by-hp-serial-range/20hp/bf20d4-lra-2004/thermostat

Good luck

Thank you!

Is that anode under the thermostat cover or do I have to remove the water jacket cover? Hard to tell in the diagram.

It's been awhile but I'm pretty sure its under the jacket cover.
When you're in there check the flush valve seal and spring so you don't get THAT dreaded water leak.
Then, NEVER use that flush port to prevent it from developing THAT leak.

The BFD 20 is an AWESOME workhorse but, like most post '03 small Honda outboards, it has that lousy designed flush port and the almost worthless accelerator pump on the carburetor.

Good luck

Thanks again!