Are you racing at NTK in Denton? I’m a member of NTK. Welcome to club. I bought a used kart with a PRD Fireball at the end of January. I did the last race of the winter series with it, then switched it to a clone/chonda. Now I’m running with a Animal in our box stock animal class and loving it. If we do brackets again in the winter series I’m planning on putting the PRD back on for some fun. The PRD is a strong motor and a blast, I just wanted to practice smooth driving and there’s a few very experienced guys in our animal class.
What gear are you running? You mentioned your mychron was broken so you probably don’t know max rpm.
On your cutting out issue, it sounds like the high speed needle is set a little lean. You can adjust the high speed needle while driving to dial it in just right. Here’s a link to the PRD manual that will help. The second link is to a PRD owners group in Australia. PRD is very popular over there. Tons of good tips to read on that site.