Mike F ,today i,m by the fire because i have a bad cold ,and ,so i will respond ,i been there and done that ,first be sure your right on with your .020 at the points ,then drop the drive shaft a nd see if it will start ,it should .next stop the engine ,remove the spark plug ,leave the drive shaft off .now roll the engine over by hand ,place a screw driver on the cam cover ,keep rolling it over ,you should hear a click ,the click is the c/r ,if you hear the click the c.r spring is to weak .and needs to be replaced .and yes you can do it w/o removing the engine ,remove tha cam cover ,roll the engine till you see the spring ,then ty a thread on the old spring ,and remove it .now do the same with a new spring ,,thats it ,now back to the click its the c/r weight ,and if the spring is good you will never hear it .and that lets the exhaust stay closed .that why is slow turning ,first time it happend to me i though it was the hydro ,as i had rebuilt it ,so i removed the drive shaft and it would start ,then i heard a clicl at the cam cover .and found the problem .and yes you still can get new springs for the c/r .good luck