I would like some advice on how to remove the air pump system. what do you plug the injectors with?

If you're talking about the ports in the heads, there are 3 ways that I know of.

You can:

1. Have them welded up,
2. Leave the stub pipes on the heads and cap them, or
3. Plug the holes with some valve adjuster screws. (This is tricky with the heads on as you can't tell how deep they are)

The first 2 are good, the 3rd is not. The seal is at the ring on the injectors, not the threads, ans using a valve adjuster screw won't ensure a seal, and they often come adrift. Correct metric caps are readily available. The Cap'n

Do you know where I could find these caps?

Yeah Cap'n... I've used the metric caps from inventory before, but can't find a place to get them locally?

Mine has #2...

I disagree. The threads are the seal. The ring on the injector tightens against the head.

See attached photo.

One of the previous owners plugged the port as shown in the picture by RAND. Recently I had an exhaust leak that I could not find until my mechanic discovered that the AIP tube had pulled out of the head.

Len is now welding this port shut. I would not use an adjust screw as there would be a possibility of it being sucked into the intake if the threads on the head were to give way as they did in my situation.

Is there any advatage in removing the cataitic coverter and replacing it with a pipe? better sound? more horsepower? cooler running? Thanks every body for air injection info, again does any one know what size caps I need or where to get them?

I had plugged mine with bolts, which I picked up at Lowe's. I don't recall the size/pitch. You can do a search, it's here somewhere.

An appropriatlely sized ball bearing in the end of the air injection nozzle seals it really well. The NPT Pipe Cap fits the threads perfectly and holds the ball bearing in place. I believe it was 1/4NPT?

Mike Mueller knows the sizes as he had this arrangement on the engine I bought from him. Somewere I have the caps and the ball bearings.

I'm sorry, you're right. It's the AIS injectors on 911s that seal with the flange. The ring on 914 AIS injectors tightens against the head, providing at least some assurance that the thing will stay in there. The Cap'n

In order for the screw to be sucked into the intake, it would have to come clear out of the head, move up to the throttle body, get past the throttle butterfly, and go through the plenum and manifold to the valve. Not very likely. The Cap'n

I have a thread (linked in my signature) about taking out my air injection with method #3 (bolts).

Sounds like... Fun with magnets?

Cap'n is right... The air injection was hooked up to pump that basically fed oxygen into the exhaust -- not into the combustion chamber. Worst that could happen is it blows out -- into the engine bay. Then you'll get a loud noise and lots of exhaust gasses into the engine bay.

Thanks to all for the advice. It is done. I used brass caps and ball bearings to cap the injectors. 3/8. I went for a test drive all is fine. It seems to run better and quieter. It is also nice not having all that junk in the way. Well off for another drive its a nice fall day in mn. 60 degrees great for air cooled engines. PEACE

With the exception of the belt driven pump, there is NOTHING removing the AIS can do to improve power. NOTHING. Glad you got it handled, though. The Cap'n