I originally posted this on X360A but since it was well received I thought I'd add it here too. Sorry for the wall of text but I put this together with the level of information I would have liked when I was going for this achievement.
Rider - Takeshi Yukio
Engine - DASA Racing 449cc 4 Stroke (A Class)
Stats - 96, 87, 22, 85 & 100
Track - Sandy Mountain
Special Tricks - Blind Faith (UP) and Rockstar (LEFT) in that order
Do this in Trial Mode so you're the only person on the track. Before anyone says this has to be done in World Tour or Single Event, believe me it doesn't. I unlocked my achievement in Trial Mode. When you go over the Vertigo Jump go straight on instead of up the steep path to the left. Follow this route. The jump before the Vertigo I got a double Y button trick in. After landing I used some boost to get moving quickly, lined myself up and then put the boost back on at about a 3rd of the way round the bend that leads to the Vertigo and kept it on til I was in the air. You need shit loads of boost and a 100% preload else you can guarantee you won't land your 2nd trick. Not much more to say other than swear excessively when going for this achievement (and try to avoid breaking things in your house). It's annoying. Simple as. Let the anger out and try again.
Again, credit goes to CheshireMulisha who got this achievement before me using the same rider but different tricks. He used Sidewinder (I think - whatever the UP/LEFT special is with Takeshi anyway) followed by Blind Faith (UP). I don't know exactly what his stats were but they were similar to mine.