Removed it today and there's oil in there, do I need to wash it out or not? If so what's the best way of doing it?
flush out with petrol then leave to evapourate ;)
Or use gunk.
I used carb cleaner on mine!
used water and fairy ..
left it on radiator to dry out proper..
but more ideal to use some form or cleaner .
I used some citrus degreaser on mine. Can get it from your local bike shop.
Gunk cleaned mine a treat!!
I ended up getting 2 litres of petrol and flushing it through, carnt believe how much crap came out, this must of made a tone of difference to the cooling performance.
fairy & water here too. brushed the outside down too and spray rinsed to get the crud out stuck in the fins.