And (according to the parts diagram) it already has a very basic oil filter. So (as already mentioned) ... clean your air intake and change the oil and filter every season (or more often for a heavily used item) and you'll be good to go without trying to make it do something of dubious results.It has a pressured oil system like many modern small engines. I wouldn't be trying to add an oil filter if the oil just sat there and relied on being splashed around. It makes 50psi of oil pressure.