So here is a GP61 Thunder Tiger I just picked up for almost nothing ( less than $10). In less than an hour it is clean. The head and piston needed another dose of Dawn Power Dissolver. I use a hard nylon bristle brush, NOT a wire brush as that will damage the original aluminum finish. First I applied heat with a heat gun to loosen it up as it was frozen solid. Once taken apart you can see the results.
MK







While waiting for the second soak on the head and piston. Off to the buffer for the crank and liner.



Back together now, all that is left to do is clean the muffler and the carb.



cleaned muffler and carb all ready to run now.