thanks for your help i check the reeds it's seat perfectly , i check the inside of cylinder its not machined properly i have bought this engine on ebay shop (slyvian1975), a friend have a DL50 bought at (peakmodel) just one gallon of running in incredible compression !!! and perf are here 7200 with 22 8 just out of the box. I plan to buy a couple of piston and cylinder to solve the problem.