250-500cc Hard thump going into first

Maybe I'm confused about the nonemclature: is SAE 80w the same as 10-w80?

If your going to use motor oil make sure it's JASO rated. Some oil (even the cheap stuff) has gas saving additives that will make your clutch slip. I use Rotella 15w-40 and have also used Mobile Delvac.

do the steps above to free up your plates. use atf or supertech oil from walmart for your flushes.dont use type f it causes plates to stick slighty.cheap is correct but when plates are free go back good oil. dont let any one talk you out of spectro 80w it is the best oil that ihave tested with husky mech on the track.pv duke is correct the oil is way to expensive for this procedure. make sure you adj inner clutch after you free up plates. all this is why your bike clunks into gear, if you want cheaper oil when things are freed up dont use automotive oil it will burn up clutches eventually.use mobil 1300 oil you wont get the false neutrals as with other oils.good luck

Could I just go out and ride it for 30 mins to free things up?

I have a similar low hour 1999 125, I just took the clutch apart and pulled the plates apart, then reassembled with all the sharp edges on the steels facing out. Run your finger across the edge, about half of mine were backwards. The way they punch them out it leaves one rounded edge and one sharp. Also inspect for notches in the basket fingers while in there.

Diesel or ATF oil in the trans. ATF works great IMO, I even use the cheapo wallymart stuff.

99wr250 yes.old3 you can run atf its just to thin.if it is colder and you ride easy you can get away with it.atf is ok for the clutches but not gearbox.i was fortunate to test with factory rider and mech and we tested and tried about every oil and combo out there. iwas shocked as to the myths vs what actually works. i also found out that some of the new friction plates used today atf wont work at all. thankfully huskys will. if it working keep using lot cheaper.old3 good advice take clutch apart inspecct put back together

I started running Amsoil synthetic ATF in my gearbox on my EXC530 and it was fantastic. The son's 2t KTMs followed ASAP. Eventually we tried the nameless brand by the gallon, same difference. Everything from 125SX to a 250 and 380SX, all ridden hard in heat and deep sand. So far so good, been a few years of racing. If we are out of it they get Rotella T, but the KTMs don't seem to care either way.