The decompression lever is broken off, and I only have the roll pin left. I am having trouble decompressing the engine a I move the pin away from me or even towards me , its difficut to spin as it is not decompressing . could i take the rocker cover off to check why  its not decompressing? I will put a few drops of oil inthe injector port. when I check the injector it has dark wet oil on it , is thatok?