So I bought a 76 CB750F last summer, with the idea of doing a mild restoration and getting it on the road by next summer. When I got the thing, its ran ok, but eventually got rougher and rougher and then stopped (this was over several weeks). When I drained the tank, what came out had a strong orange/reddish tint to it, and I thought "uh-oh, rust." The tank is lined with what I'm reasonably sure is Red Kote, and from what I've read, that can cause the discoloration I saw. Before I go through the aggravation/expense of stripping out the old liner and relining, is there some simple, easy, foolproof method to determine if Ive got very tiny rust particles in my gas?