[ScooterBob]

I set about to de-coke my trusty old flathead Dnepr one afternoon out of sheer boredom .... it ran just fine, but I was curious. Long story short - it ran like total s*#t when I was done ... !! I had lowered the compression back to stock by removing the quarter inch thick piston-insulating crust! I'll never do THAT again ... Hahaha!! I knew NOT to de-carbonise the tops of diesel pistons - but I didn't think it'd make THAT much difference on the old pig-iron bike. I had to ride it around with the air shutter partly closed to build up a good coating of "black compression" on the piston crowns ....... sheesh!