I painted the entire shell with the red color, then masked off the areas I didn't want painted yellow. To get the stripes I cut narrow strips of drafting tape (?) and applied them to the areas that I wanted to keep red. After the yellow paint was applied, I simply pealed the tape off.
There was some "blow by" paint that got under the tape in a few places, so it wasn't ideal; but I just touched it up the best I could after the fact.
It was primarily an experimental paint job. For the yellow I just used Testers from a can because I didn't want to take the time to clean my air brush. I should have used the air brush! Next time I'll take the time to do it right, and the results should be a lot neater.
I suppose the stripes could also be done with decals strips which would be neater and cleaner, but I was afraid that I wouldn't be able to match the red of the engine.