Sounds to me like an exhaust leak that seals itself when everything warms up or as WhoDatInDaMud says look for a arcing of the spark in the dark. It will be a nice blue color and moisture will cause it but once it warms up and dries everything the arcing will go away.

 

what octane fuel are you running to? this probably has nothing to do with it but run higher octane in it the 650 is a higher performance engine and i found out running 91 in it makes it run better and smoother and which is better for when it is cold to seems like a person has less of a chance of ice getting in the carbs

 

[img]i/expressions/face-icon-small-happy.gif[/img] And the prize goes to Hondabuster !!! I checked the pilot screw settings: one was out 1.75 turns and this is no B.S., the other was all the way in. Set them both at 2.25 turns out and no more lean miss or hesitation right off idle. Dont know if the dealer played with these or if it was a factory goof.

 

Didnt know there was gonna be prizes....just glad to help.
That sure is odd, that one of the screws was left all the way in, guess it goes to show, even new quads can come with problems.

 

Im leaning more toward the dealer screwing up when he rejetted for altitude. I've found a few of his screw ups and have switched dealers. I was very surprised it even idled with one all the way in but I guess there is enough carb system overlap involved. Many thanks again.