Plus double check your battery connections. Several months after i bought my TBA, it was losing power upon acceleration. I would crack the throttle and you could just feel the lack of power. I know it sounds unlikely, but i remember reading somewhere (probably here) to check battery terminals. When I did, they really didn't look bad. I could move the negative terminal lug, but it wasn't loose or too easy. It was essentially tight in my opinion. But, I wire brushed the terminals and reconnected the battery. The difference was immediate, it ran great. However, mine did not backfire nor surge. But these electronics don't like bad grounds, etc.
Jay
