Suzuki DT140 Cuts out at 2000 rpm

[bushpilot47]

I have a '93 Suzuki DT 140 that starts and idles just fine. When trying to accelerate when it hits about 2000 rpm the motor dies. It will re-start and idle just fine. I had it in a shop and they cleaned the carbs supposedly and checked it over, but couldn't find a problem. Another shop told me that the CDI unit was bad causing the timing to not advance properly. I bought a CDI unit on eBay and replaced it and the motor does the same thing. That tells me that the CDI probably isn't the problem. I have tried it with a different fuel hose and tank set up. Same thing. Any ideas will be much appreciated.