HBW,
Not much info to go on. Did it simply die or start to struggle for power, to me though sounds like maybe the bike is running out of fuel due to a restriction in the line/tank petcock? You mentioned oil pressure but, that is normal when the bike is off/dies but, nothing about spark? Usually one of two things factor in on a bike, fuel or spark. If it has leaned out on fuel it would stumble a bit and die for spark it would just die. Even turn over like it has no compression. Jez my 2 cents.
Trumpy
