you said you replaced the calipers. and pads. or just pads? if you changed calipers, did you change the crush washers on the banjo bolts? they are usually a one time use. are the pistons in the caliper sealing properly? the whole key on thing is weird, the only time that should effect it is if it has abs, which yours shouldn't. make sure the lines aren't being kinked any where that has moving parts when the engine is running. try rolling the bike with the ignition off and see if they still lose pressure. good luck man, and by all means if you figure it out, let all of us know.