Help !........I have an Atco Commoder B17 mower....which has had 4 or 5 engines on !.

I've just realized what I think has caused my many engine failures...

I live close to a river and cut the river bank outside the bottom of our garden...to make it look nicer and be more pleasant for walkers.

When I cut the "slope" up to the bank top, I think this is harming the engines lubrication capabilities and causes damage to the engine thro lack of oil lubrication.

My neighbor cuts his part of the bank....slope and all....and never has any bother !

Am I right in my theory on why the engines are seizing?....and if so what kind of engine do I need?

Can I get a different engine for my Atco Commodor which will stop this problem or do I need to buy a different make lawnmower?

If so....which????

Many thanks !