Blurpy

I seem to be having a problem with my Hawk cutting out at a fairly low top speed. It is at about 135MPH and a little over 8,000RPM. Now its only does it in 6th gear. All other gears go over 9,500RPM no problem. The speed I got is actual speed off of a aftermarket Speedo Computer. The bike speedo says 150-155. I was wondering if these bikes have some sort of speed govenor or if maybe I might have an actual problem? If so I'd love to hear suggestions on what I might do to solve this?

1988 SuperHawk
D&D Exhaust
K&N Air Filter
Factory Pro 4 degree Ignition advancer
Factory Pro Jet Kit (182F, 185R)

Blurpy

Now one other thing I did notice is that its not just stoping at that RPM but it falls back down every so often when doing that speed. Almost like its cutting out. It will climb to about 8,500RPM, but it will fall on its face for a second and slow down again (to about 8,000RPM), and then come back up, and so on......... Any more Ideas???????????????

1988 SuperHawk
D&D Exhaust
K&N Air Filter
Factory Pro 4 degree Ignition advancer
Factory Pro Jet Kit (182F, 185R)

Blurpy

This is not a track bike it is a weekend road machine. The main reason for the 20 MPH difference is because of a different rear sprocket. I was told that it might be an ignition coil problem?? Does this theory hold any water or is this guy full of it??