Hi, i am putting a 2005 13b 4 port in a jet ski, i dont have the engine loom or ECU, i have made up a carb manifold with webber twin 40s, i have all ignition coils and crank position sensor, is ther anything i can make or anything i can buy( i am electronically minded and can prototype) that will give me a spark and what are the angles of spark and firing order, is it 120deg per rotor housing and what angular difference is ther between the two rotors and how far after TDC do i need the spark??? hopefully someone can help, i am a crazy english guy!!

 

Because there is no distributer on the engine, you are going to have to have some sort of ECU to make spark and to make changes to the timing. Since you don't have a fuel injection system anymore, I think that the Mega Squirt ecu may be the best option.
There is a RX8 club in the UK with some very talented people. They may be able to help. Here in the US, there are marine ready (RX7 type) 13B's available.