RE: OS GT33 33cc gasser
You do have a warranty. If you had not run the engine you have have been able to return it directly to Tower within 30 days, same as most companies.
Most companies, including DA will not give you your money back if you have used the item but will repair or replace it. Buy an engine fron Horizon and you will be treated about the same as Tower. However, if it is evident the engine was run lean you will be paying for replacement parts, which is only fair.
Buy something from DA and try to return it after 30 days and see what happens. You will be charged 25% restocking plus return shipping.