Greetings sir Luke
my 5 cents worth
So the bike was going good then it boiled and fouled the spark plug.
Replace spark plug and rev the bejesus out of it after a downhill.
:huh: :dry:
I have the 15 model 300 husky and the set is as follows
necj #3 (suzuki needle)
165mj
38 pj
as 2
red spring
but been 600m up the settings should be a bit different. 
just rev it to blow out the oil, my son wouldn’t rev the stuff out of his rm80 and he was always fouling plugs. :huh: :dry:
If the set up you were using was a good thing……. something has changed :ohmy: :ohmy: :ohmy: :ohmy: