While checking over my K100 I've found some scoring on pistons 1 and 2, engines a bit smoky, with cold compression of 155 psi. should I continue to run the engine?  

   

Another victim of the endoscopic camera availability.
Visual inspection is vain, until you find a big hole in the piston dome.
If you want to know how is your engine, you need this:

And that :


And a little time to open the engine to check and measure with accuracy.