Crazy Air Filter
 

Preparing for a brutal winter headed our way (according the the Old Farmers Almanac), I've been cutting cord wood and driving the wood up to the stack with the 1440. For the last two weeks or so, the 14HP Vanguard V-Twin in low idle has been awful rough. Plugs, fine... new fuel, fine...carb clean, ... no fuel restriction...but just can't figure out what the devil the problem is. Air filter looks nice and clean and the pre-filter is clean as well. But, as I've not changed the air filter in 2 years (kept clean by blowing out with a leaf blower from inside out), I break down and spend $20 (kind of a lot for such a small filter) on a new pre-filter and air filter.

I fire it up, choke off.....low idle nice and smooth again. So I guess my question is why would an air filter affect low idle and not any other throttle position? Has anyone else experienced this same issue? Are Vanguard's super sensitive to air flow? Seems like you can't eye-ball the filter like others, you just have to change it. Is there any other source other than B&S for air filters less than $20 that would fit?

As always gentlemen many thanks,

ccguy
Western MA
1994-1440

My neighbor has a vanguard that does the same thing.
Put a new filter in it and it will smooth right out.