Looking for a laundry list of things to check to isolate a high RPM (8000+) miss on my turbo/EFI DS. The motor won't rev out all the way to 10,000RPM, it breaks up at ~8000RPM and higher. Intermittently I am able to rev all the way out.

 

Possibly electrical? Maybe CDI unit is going bad?

RoostKing...

 

I would check the spark plug gap. You may check the plug cap also, they have been known to have the wire come loose inside the plug cap (on 250R's).I know a weak spark will cause high RPM to break up. You might want to double check the fuel supply, pump may not be supplying adequate volume. It sounds like something simple (hopefully)
goodluck