I figured it was time to improve my MPH so I changed my 600 DP for a 750 vacuum secondary. It feels slower now! I know seat of the pants testing is worthless, so I guess I will have to test it at the track next weekend.

The secondary valves seem quite tight and take more than a little effort to get them to move. Is this normal? On my old carbs it seemed as though they could be moved by barely touching them.

 

They sell kits for that for like $20. Comes with several different Secondary springs so you can have it set the way you want it.