Mate I think I may have the answer. Had a tank on an 18 fully rusted inside. one hand full of blue metal inside. a good 3 mins shaking the hell out of it. empty out then put the blue metal back in, minus rust, repeat 3 or 4 times. clean out well with straight fuel a couple of times then whack some 2stroke fuel in it with a new tap and filter and you are away. have used this process about 5 times the more you shake the better.
my 20 cents worth
Sean
