Anyone know the proper machining bore specs for a Keihin injector (Merc. p/n: 805225A1). I know the seal size is .550 x .311, is there an stepped drill available like some of the other injectors?

When I was fabricating intake manifolds and fuel rails, I used a 14mm cutter and a 60 degree chamfer.

Thanks but I don't think you were using Keihin injectors. These things measure 14mm on their O.D. and the seal has a 21.5 mm O.D. I just ordered a 21 mm center cutting end mill. Hope it does the trick.