The only one I have installed was on a Victory CC. It was plugged into the stock controller as an add on unit. I believe that is also how the one on my buddy's HD was too. With that I think the stock unit is still there and does other functions on the bike and can not run without it.
thanks davej, I sent an email to Kyle to see what he thinks. From what I can tell so far the earlier carb
'd bikes have ignitor units while the FI's have an ECU controlling the ignition and fuel. So like you said with the Victory and HD the Dynojet I have also seems to be an add on running next to the ECU. I can see the ECU there next to my battery. I'm just not sure how or why this Dynojet is hardwired into wires under the tank going to the injectors. I thought all of these aftermarket boxes were plug and play. maybe this shop found a way to charge more money?