Need to stop thinking on the cheap, just a annual service is a form of guarantee the machine will continue to operate, spend a little on a annual service or a lot later when that engine/machine has issues, and a service is more than a oil/filter change, it is also a Inspection of the components around those areas you have to access to change the oil and filters, use your eyes and look at the components for loose, damaged, can be adjusted, leaks, frays, rubs, or was fine last time but was a tad bit off kind of stuff.