Dear mohansivaraman17, Masturbation enjoyed properly at your pace is not going to harm you , your health and your sperm count and motility in any way . it doesn t give any health problems, the semen viscosity varies day by another day depends on what you eat how much you take liquid , don t bother about the viscosity or thickness . one thing more the semen in the body is more viscid and when it comes out of male body then it has to get liquefied so the sperms can swim to ovum it helps to your fertility if it will liquefy then its abnormal.