I did 2 run today on a stock engine .first on with a flightworks 200 pump and again with a jetjoe pump.It got to 720 with a 44mm dia tail cone. stock clearance motor . can not say for sure on thrust as it was on test stand and I check thrust in air frame tied to strain gage. I was surprized that jj pump ran just as good. It is 0c out and it pulls hard at this temp.