OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Chainsaws and Concrete Cutters McCulloch Chainsaws McCulloch 110

I have a MAC 110 that runs fine, only problem is that the muffler retaining screws keep coming loose. I tightened them so many time now that the threads are stripped in the head. Any ideas on how I can fix it?The saw has not had a lot of work and is still in good condition other than the muffler.
Thanks Keith