Evan I have allmost exactly the same problem.....I believe it's the chips, I have a A/F gauge and it keeps going to lean at the 3k to 4k rpm mark......it's also the gas for me.......I thougth it was overboost but it's not at all violen unless in full throttle but even then just hesitates and does not want to ..go!
But not the hard shaking that people have mentioned just a little

 

You may want to check the alingment of your magnetic sensor for the flywheel.

 

You may want to check the alingment of your magnetic sensor for the flywheel.
fast44

how is that best done?