njl

I've got an Irving 46 engine mounted inverted in my Home Run.
I fly from a grass strip and I've notice that the carb often picks up bits of muck (grass, dirt etc). So I was thinking about fitting an air filter. On one occasion I had to remove and clean out the carb before I dared to start the engine again. So I though it might be worth investigating an air filter. Has anyone tried fitting one and are they any good? Can you recommend a good make or a good home brew solution.

Thanks
Nick