Guys I just bought a 2020 kx 85 brand new did the break in all except for the teardown check, replaced the transmission oil Lucas oil semi synthetic and the fuel mix oil 32 to 1 Lucas oil 2cycle and the bike has quite a bit of blackish grey sludge after every ride leaking from the vent tube tje oil level is good I suppose about 3quarter up on the sight glass and it runs good. Also when I bought it they told me the carb was gummed up and they had to clean it I guess from sitting for so long. As well I cant get the idle correct it wants to stay at high rpms when revved and takes about 5 seconds to come down then wants to die. I have 30 day warranty should I take it back to be checked, i have played with the air screw and idle screw with not much change and am worried about the sludge as it seams excessive about the size of a couple quarters every time after riding and sitting for an hour or 2