hsk600

I have a tecumesh hsk600 1700s that wont start. It has spark. I tried to start it but when it wouldnt i tried to put gas into the cylinder head and then start. at that point the starter began to kick back (high compression i think, not a broken key) and while exhaust came out the engine wouldnt...

Got a handful of tecumseh hsk600 engines. Recently had good luck putting a HSK850 on a pocket bike, anyways Im gonna toy with one of these engines. Have the intake ported and going to shave a little off the head or cylinder. YAY? NAH? Also heard these engines are known for weak piston rods...