LPG vs Diesel..

Fitted nitrous/fuel injectors in a lot of bikes and cars. When drilling the drill swarf all goes outside the manifold with the exeption of a few tiny bits. If its soft alloy then its not going to hurt anything, so dont wory! It just gets spat out the first time you hit the throttle. When tapping the holes just gob the tap in grease and most of the swarf sticks to the tap. Again no problem. If you still worry then remove throttle body/carb or whatever (usually a few nuts) and shove a tea towel down the port runner to be drilled/tapped. Once finished yank it out. Repeat other ports.

I agreee, I used to install vacuum operated valves to switch off fuel to the carburettor when descending a hill or decelerating. Again this required drilling into the inlet manifold, and with care it's possible to have no more than a tiny quantity of swarf entering the manifold. The alloy will burn in the cylinder and be expelled on the exhaust stroke.

Another trick to ensure that swarf isn't a problem is to blank off the throttle and put a compressed air supply on the manifold. On beakthough swarf is blown out.

What they all said.

Drill slowly, when you get to breakthrough just take it steady. The tiny amount of swarf that does get through will burn on the first firing stroke of each cylinder.

My kit is the Aldesa one. The bloke who sold it to me got into trouble from the uk importer seeing as mine came from Belgium IIRC.