The pinch test is to get an indication of whether the idle mix is rich or lean so ~8K is far too many revs, you should be down around 2.5 or 3K.
Adjust the idle speed down to where it seems close to stopping then pinch the fuel line. If it stops almost immediately then the idle mixture is too lean. If it begins to increase revs noticeably after a short time (maybe a few seconds) then it's too rich. The reason is that excess fuel tends to collect inside the crankcase at idle so this has to be used up before the mixture begins to lean out. What you're looking for with the pinch test is a slight increase in revs before the engine starves for fuel...in other words, just a little on the rich side.