When I removed the primary fuel inserts one broke, this was the type that has a 45 degree angle at the tip with no holes on the end. So I went to mazda to get the part replaced and they told me it had been superceded by the type that is used in the secondary injector ports. This one has a o-ring gasket built into it and has several holes at the tip.

So I just ordered a set of two to match. So now I am running all 4 inserts the same. I wonder why they replaced the old style? From its appearance it would seem these would emmit a better mist of the fuel. This is the type that has also been used in the FC 13b's.

Anyhow I'm leaving it up to the information Mazda has provided me that this will be okay. The thing is there isn't a slot on these new inserts to align up with the slot on the port, like on the old ones.