I have tried to do some research but I have not been able to narrow down my problem. Maybe you guys can give me some advice.
Had this bike for about a year. It was bone stock, all mods done by me. Relevant mods: full system, velocity stacks and quick throttle (all done recently). Bike has fresh fuel, a clean air filter and chain. Battery is strong and the bike has only 3500 miles on it (I know, I bought it with half of that a year ago). I have not let it sit without fuel stabilizer or being run every couple weeks.
After the last of the mods were done I took the bike to Apex Moto, in Anaheim, to get the bike tuned. Power curve came out smooth. A/F mixture is clean except for a small dip at about 10k RPM. See attached.
As I was riding home I noticed that under full acceleration the bike would loose some power at about 11-12K RPM and then pick back up. It only happened about once or twice on the fwy and I didn't think too much of it since one of the throttle cable housings were broken. I was thinking the cable was sticking.
Since the tune I lifter the tank, air box and replaced the throttle cables. Install went fine. Started right up as before. Took the bike to Buttonwillow this last weekend and thats where I really started noticing the problem. Under any heavy acceleration the bike will loose power around 12K RPM. It happened almost every time unless I was going gentle on the throttle (but a loss of power was still noticeable, just not as pronounced).
I am planning on lifting the tank again and making sure I am not pinching any tubes/lines. I am pretty sure they are fine but I will check anyway.
I talked to Apex and they will take a look at the bike but he suggested that it might be the change in altitude between Anaheim and Buttonwillow. I want to beleive that but since the bike consistently dies at 12K I am thinking its not environmental.
Does anyone have any experience with this problem or any relevant