[Gearhead999]

I would check the chart you received with the carb about tuning it. There is a chart in the manual.

If the carb is too lean at cruise, if that is where your surge is, it tells you how to richen it up. Very easy to understand and the modifications are easy too. Also, check the float level, just because it is a new carb out of the box, doesn't mean it is right.

I would also check for a vacume leak. That will cause a surge.....as in A/C, automatic trans modulator, vacume headlamp doors.