Lower unit repairs

When I opened the water pump housing I managed to break three bolts of total four.
I was not event using extensive force, several years of maritime use had locked the bolts badly.

It was quite hard to get the part number 84 out due broken bolts. I finally managed to get it out but unfortunately a small piece of exhaust pipe wall broke also.

In order to repair the lower unit I need to get three 6 mm bolts out and fix the exhaust pipe wall.

Broken water pump bolts and a missing piece from the exhaust pipe.

How hard can it be to remove broken bolts from outboard lower unit ? Quite hard indeed!

I tried several methods:

- Put a nut with permanent Loctite, allowed 47 hours to affect => Loctite didn't hold when opening.

- Stud remover was not able to get hold of the broken bolt, there was not enough length in the bolt.

- I tried to drill hole in the bolt and use bolt extractor, it's very hard to drill since the driveshaft is so close, I used a broken bolt extractor but unfortunately it broke also leaving the carbide tip inside the bolt 😭

I was thinking to obtain a Rescue Drill Bit and use it with Dremel but it's not cheap and I guess you need to order it from the US.

I took the lower unit to a local outboard repair workshop, they said that they cannot do anything as they don't have suitable tools (or even interest...). However they recommended an engine machine shop, as I live in the Helsinki capital area in Finland I took the lower unit to GT-Motor Oy

They are certainly not specialized in outboard or boat engines but they said they will give a try,
after a week they informed that bolts were removed successfully and even the threads were intact! Apparently they used welding and one of the bolts gave more resistance than the others.
I'm quite happy with the outcome and can totally recommend their services!

Bolts extracted by engine machine shop!

Now I needed to fix the exhaust pipe and also reinforce the front stud which was quite rusty.
I don't have aluminum welding tools or skills so I decided to use Loctite Power Epoxy Metal.

The end result does not look fancy but I think it's quite strong and can also withstand the temperature of the exhaust gases.

Exhaust pipe wall fix using epoxy.

Exhaust pipe from other side.