Help! Anyone here familiar with vac and pressure testing a 4-mix engine?

[ANewSawyer]

Been playing around with the KM-130 I got. But the pressure and vac test have me confused. I am going through what I assume is the impulse line, from crankcase to carb. Pressure or vac will slowly drop at the rate of about a point a minute when I don't move the flywheel. I haven't taken the time to see if the pressure or vac readings stablizes at a certain point. If the reading stabilizes it is at a low pressure/vac. If I move the flywheel, things go crazy. The needle will drop below the non-movement reading, then shoot over it only to settle below the original reading. That is if I can turn the flywheel that far. It gets so hard to turn by hand under vac/pressure at a certain point that I won't turn it for fear of breaking something. Help!

 

[ANewSawyer]

Going to go back and tinker with it in the morning. The stock impulse tube was leaking at the barb when I tried tying into it. Now I putting the tester directly on the barb. I am using thinish gasket material for the muffler and carb block off. Holes were punched in the material to allow it to slip over the carb/muffler screws. I could have omitted doing the extra work of fitting the gasket but forgot about the simpler way. I wonder if the gasket material doesn't give enough to seal the intake/exhaust. New valve cover gasket but I forgot to wipe the mounting surfaces before I put the cover on. I don't think that will be a big issue though. That thing coming out of the crankcase to the bottom of the carb is the impulse line right?