Hi Grumpy,
Mine does not have a yellow clip and is obviously single cylinder. It is an all plastic affair with a kind of over centre locking arrangement for the air filter cover. It may be ok, it just feels like it is cheap and does not lock down with a positive feel.
I would suspect that if the plastic shroud was twisted or otherwise damaged, it would not seal very well. Also if care was not taken to install and seat the air filter element correctly. Luckily I have always looked after mine and the plastic has retained its original shape.
After 9 years, I have not had any issues with dust etc. in the engine. I am so glad the starting issue has been rectified though. We should receive our new Greenfield in a few weeks so the Toro will be up for sale. It will be a bit sad to see it go - I've spent many hours with my bum on that seat.....
Andy
