748 starting problem. Please help.
 

Guys i'm having a nightmare getting the bike finished. I've got a 2002 748s which i've rebuilt. Its fitted with a datatool system 3 alarm. When i turn on the ignition the fuel pump doesn't prime. I've checked and there's no power to the pump at this point. If i put the side stand up and press the starter i get power to the pump. The bike starts and runs as long as i'm pressing the starter button. As soon as i let go of the button the bike dies instantly. Its as if i'm only getting power to the fuel pump if i press the starter button. I've changed both relays under the seat and no change.

Does anyone have any ideas on what to do next? I'm thinking ecu problems now :0(

I doubt it is the ECU.
My 748 had the same alarm on it and the first thing I did was remove it. Alarms are in my experience the cause of many problems.
I also by passed the side stand cut off switch so the bike would run with the stand down.

£1 say's it's the alarm to blame.

Chances are the alarm is cut into the fuel circuit, so when the alarm is armed the feed to the pump is open circuit and then with the alarm turned off the circuit is complete. So I can't see why the alarm would cause the problem your seeing.
I'd certainly be looking at the wiring for the RH Switch, not just the water proof Amphenol connector but also the round multi pin above the battery

God i hate myself sometimes. I had managed to wire to RH switch wrong. The clue was when the kill switch was off and i pressed the starter botton the fuel pump ran. DOH!!

I spent ages looking at the wire diagrams before the light bulb moment

Well thanks for the help guys. She's alive hahahahahaaaaaaaaaaaa