my 309 is suffering with black chocked up spark plug after little use, any ideas anyone,  
also can anyone tell me what spark plug I should be using as the previous owner dogged the wrong one in, 
I`m also not sure how much fork oil I should put in, I`ve been told 240cc per leg, but they seem to be leeking and I`ve just had new fork seals. 
one more thing, I`ve put 100cc of two stroke oil in 5 litres of optimax, is this right or could it be contributing to the spark plug fowl? 
Any input would be great cheers.