first off, you must losen up those crank brgs. or the balls won't roll just slide in their races. very bad news!!!! what i have done in the past is partly disassemble eng. remove carb, muffler, and back plate (probly will need new gasket or make 1 yourself, easy to do) with eng. in oven heat to about 225-250 degrees for about 20-30 mins. this will soften castol gum and varnish. let eng cool a LITTLE so you won't burn yourself and soak eng in some fresh glow fuel and start to spin eng to get sludge etc to be broken lose. you mite have to go thru procidure a couple of times to commpletely clean eng. CAUTION, CAUTION!!!!!!! do not put glow soaked eng back in the oven with fuel in it, it will catch on fire and so will your oven on fire!!!! [] flush with rubbing alcolal and dry with hair dryer or monokote heat gun, then do the oven thing as needed. just always dry eng out of that fuel/and or rub alohal. try it works for me.