the decompressor on the XX cam only works if the valve lash is set with just enough space to force the right side valve to open .
to much lash ,then the valve is not bumped .
next time you remove the cam look at the decompressor . you will likely see a shiny spot . the more that spots hits ,the more it wears ,the more it wears , then less valve lash is needed to them bump the valve open .
sad that we can not get that part .
751 ,barker pipe,290 Web cam,+3 stroker,TB bored to 46.8 and moved back from head 1 inch,+3 big bore , +1 intake valves, Hard Welded Rockers,KW springs, ported, clutch mod , air box removed ,Cat oil mod, dynojet commander V w/auto tune , lowered rear end , TRX450R front shocks ,