From experience, I'd advise that you check it periodically. How do I know?

Well...I was flying my 1/4 Fokker Dr.1 with a Zenoah G-38 at the Danville, VA giant scale fly-in several years ago. The engine, which had run perfectly for two years, began to sputter on acelleration and didn't want to idle well. Like a moron, I ignored these warning signs and taxiied out for takeoff anyway. I made the takeoff rollout and lifted off the ASPHALT runway. About 10 feet in the air, the engine said, "I quit", and did. Now, 10 feet of altitude at just-over-flying speed isn't enough to save a Dr.1 when the engine gets real quiet. The resulting crash sent it back to the shop for a month while I built a new top wing, rebuilt half of the middle wing, and fabricated another set of cabane struts. It also ended my flying on the second flight of the first day of a two-day event. [:@]

The autopsy found a clogged carb filter screen. A $5 rebuild kit got the engine running perfectly again.

Now, I filter my gas three times. Once in the supply can, once at the supply filling barb, and once in the onboard gas tank klunk. I NEVER let the ends of the lines touch the ground, and I listen real careful to what the engine is telling me. I also check and replace the carb filter screens about every 25 flights.

Dr.1