Engine performance issue.

Try this. Clean and adjust the carb. Turn the airscrew out 1 - 1 1/2 turns. See if it gets better. While your in the carb, check the size of the pilot jet. It should be a 32.5. I've seen MANY a Blaster that needs a 35 pilot. It sounds like a carb issue to me.
 
Did you plug where the oil line used to go into the crab ? Also you said you leak tested, how long did it hold pressure for and how much if any did the pressure drop?
 
Did you plug where the oil line used to go into the crab ? Also you said you leak tested, how long did it hold pressure for and how much if any did the pressure drop?

I did cap off the oil line. When I tested it last it was only holding about 2 psi cause it was leaking from the exhaust flange. I fixed that hoping it was all but havnt tested it since. I did notice that it gets significantly worse when it warms up...
 
if you have not cleaned PILOT JET in 4 years do it know..
that aircrew looks turned out way to far...how many turns is it??
is your idle screw on top of carb working at all??
carb plus idle 1 1 2 big 1 1 1.jpg