4100 wont start in cold weather

[wrede]

I recently had a problem with cold starting on my 4300. I used diesel 911, etc. and it would sputter and die. On a lark, I removed the air filters and it fired right up. The filters can collect moisture and then freeze, cutting off the air, or at least that's a theory. I replaced the filters and now it starts perfectly even down to zero or less.