Greetings Carl, I'm afraid I dont have an answer but was curious if your problem and problem I have w/my 740GL is the same...... Ive replaced pretty much same parts as you. My problem is after warming up and then once heading down the road the engine "bogs" under acceleration...let off its ok. If I turn ignition off and then restart (I call it re-booting)it typically runs normal. Ive noticed it also is a bit sluggish at times and other times has the normal "pep" i'm used to. Where is the airbox valve.... how much was it and whats the IPD catalog? Sorry to ride your tail of your post but I'm getting ready to head out on road for work and like to have my old brick in good running order. Thnaks for any input. Fairway