hi, just got this cd-10 5.5 and it has been sitting for over two years or more,so i cleaned tank out real good and put new 16-1 gas in put in barrel started but would not stay running, very erratic would not , it has blue spark and pumps water ,so i thought before i got a carb kit for it i would check the compression on it first,so i rent one and screw in until snug,leaving the other plug in and pull rope 10 times and it shows 30 psi.then try the other piston and 10 pulls and it says 30 psi i have never done a compression check before and wondering if i 'm doing something wrong, i thought it should be at 80 to90 psi, then i seen somebody said as long as both had equal psi probably would be ok.any thoughts? thanks..