Well, I would stay away from striping a job like you just described unless U are a very good pin striper or you have a lot of time to tape either side of the pin stripe then use a brush(stripping) to fill the gap between the tape in. You can tape off the flames, shoot the color of your outline, then tape off your out line (butting the tape up against the original flame tape), then re-shoot the base color, then airbrush the edges with your color shifting paint. But that's a ton of work for some stripes. Just drop shadowing it would probably be your best bet and easiest to do.
I'm guessing you are using black for a base or something very dark. If you're using black then it's real easy for the drop shadow because you can use the same color black to go over the flames and not have to worry about drop shadowing the rest of the bike. Just tape off the over lapping flame and use an airbrush with an over reduced black (Normally you over reduce anyways to get better flow out of the airbrush). Then point and shoot. Start with the least amount of pull back on the airbrush as possible because its always easier to make something darker then have to lighten back up /ubbthreads/images/graemlins/bigokay.gif.
