Hello Will,
Best thing to do is pull the air cleaner apart, there should be two mesh cages, one is part of the main air cleaner body it wont come out the other should be stand alone, then immerse all the components in kero for a couple of days to loosen all the gunge up then scrub it all with an old dish brush, when you think its not to bad blow it out well with compressed air, i have done hundreds like this and you can get them very clean, when it is done fill the bowl up with clean engine oil to the level mark.
MC
