Peter wrote: On cylinders 1 and 2 you will get a lot of rainwater getting in. Peter, I seriously doubt that. I assume that #1 and #2 are the forward cylinders on your engine, With my TCM IO520BA, they are in reverse order, the even are on the pilot side, numbered from the front to rear as 6, 4, 2 and on the RH side the odd cylinders are 5, 3, 1. The injectors are well below the fins and down...