you may need to strip the carb and check that fuel pump manifold has not dried out, I found that if I do not use my 36 for a while it tends to start but not rev up.
The link below takes you to a handy ref doc for the 36
http://www.mymowerparts.com/pdf/Husqvarna_Parts_Manuals/I9701030.pdf
dazzer, July 2008
