I am a complete newbie to ECU tuning but as I have good knowledge of cars, bikes, engines and electronics I thought I'd try my hand at trying to remap a Delphi MT05.2 ECU on my ZNEN Fantasy Scooter after upgrading it from 125cc to a 150cc. I am using the HUD Hacker software with a laptop.

I have ridden the bike with the big bore conversion and a standard tune and am getting a P0174 code on the dash, the bike is also a big sluggish and won't go over 50mph...

Can anyone offer any help or advice on remapping the ECU to correctly configure the ECU for the increase in cylinder capacity, and also, is the P0174 related to the change or is it a separate problem?

Many thanks!