Depending on your POD. If we are talking about 1912 or so, the Ottomans are in a world of hurt. They should have cut their losses and ended the Italian war. This would have saved a lot of resources to put into the Balkans
The other big thing will be an alliance with Romania against Bulgaria. Romania joins the second war against Bulgaria, so there's hope here. If they do, then the balance of power is turned in favor of the Ottomans
With an earlier point of departure, there's more the Ottomans can do. The best thing they can do is get a navy strong enough to defeat Greece. If they have that, not only will they knock out the Greeks but be able to bring their troops from Syria
The Ottomans aren't in very good shape in 1912 and they are vastly outnumbered. Their collapse was quick and complete. It will take a lot to change that
what efect would i it have? well the ottomans would enjoy a respite for a few years and the Austrians won't have to worry about the Serbs