Bad grounds definately cause problems but with out seeing it I couldn't tell you.I bought the Muzzy power up package from my local shop in Vancouver Wa, I got the CDI installed right away and it seemed to work great. Then on Saturday I installed my new Muzzy exhuast. It still seemed to work just fine, I let the exhuast get hot as the instructions say and retourqed the pipe nuts . This morning I went out to move it to the other side of the garage and it was back fireing, I backed down the driveway and it stalled out on me. I reread the troubleshooting info and reinstalled my stock CDI, it fixed the issue, I reinstalled the Dynatek cdi and it went back to the same thing as before. This is the second CDI I have gone through. The first was the VDI unit and now the Dynatek. Has anyone else seen this? Could this be because the grounding recall on the card heaters?