i am guessing this stupid vacuum slide is the culprit..maybe a needle change? my 650l has been opened up etc..dynojetted by a local shop..i went from a 150 to a 160 main..and from a 152 to a 155 idle jet after doing the cam..runs strong..but if you let off after hard accelleration and hold the throttle it seems to lose fuel..dies out for a second..somtimes in complete off throttle it will die. it pops on decell also..it is fine if you let off slowly,but if you quickly cecrease to half of less it will act as if you hit the kill swittch and turn it on again..i am almost at sea level..any ideas of slide replacement or needle? how about an edelbrock carb? i dont want to fork out 500 clams unless it is gonna make it lots better..i would appreciate any help! thanks!