I'm cleaning up a 041 AV Farmboss for a friend of mine. Cleaned the airfilter, dumped the old mix out and put fresh mix in, checked the plug, checked compression (165 #). Popped after 5 or 6 pulls, fired after 2 more. It idles pretty rough. In the upright position, the saw idles way too slow, when I lay it on its side, the idle picks up. Do you guys think this is carb related or crankshaft seal related?