Working on the engine AD290 Arona

In these rainy days I have planned to do some maintenance to the engine.
Being a 45 years old engine and not knowing his previous owner/history I have doubts on what to do.
Shall I just use it as it is (it starts first go and sounds good) or shall I do some maintenance now that it is on land and easy accessible but risking to break some parts that are out of production?
I went for the second one and it was a good choice.

I am only planning to open the oil pan to check inside the engine and to open the flywheel to check for any signs of leak and also to take a look at the gearbox.

Although the engine oil looked fine once opened it oil pan I have realized the the internal pre-filter was almost 90% covered by sludge. this meaning that I would have had some serious problems not to far away form now if I didn't check.
This pre-filter didn't come off easily (as surprisingly all other bolts of the oil pan did) so I have decided to use a little basin filled with diesel so to let it work overnight and hopefully dissolve the sludge stuck on the inside of the filter.
Also the pan it self needs some welding as from the inside you can clearly see that there is a crack probably due to an incautious landing of the engine,

After welding the crack on the oil pan I have scraped away the old paint, sprayed 2 layers of anti rust primer and then varnished.

The oil pan needed a new gasket. As I did this before on another engine I've used a layer of cork. This time I will try to use only cork because I am afraid some sikaflex would spill inside the engine when tightening the pan to the engine.

 


Next step was to checkout the flywheel.
Once opened the front cover I have had a really bad impression of the status of the flywheel (all rusted) probably due to lack of attention from who did this job before... there was no seal on the cover/lid so seawater and generally salt could easily penetrate inside and do its work.
Luckily it looked much worst than it really was. I have cleaned the wheel with some wd40, then some diesel and manual sanding. looks perfect.
I have also checked the starter engine gear.  general cleaning and some grease.