So it starts up and runs awesome now after some tinkering with it. I pulled the plug again to check it and it was pretty black. I turned the fuel screw all the way in to 1/2 turn out. now it seems to run much better, still cant achieve an idle though...

 

Those are classic signs of pilot jet too big. With your pilot screw placement, clockwise is leaner, but it can compensate only so much for a too-big pilot jet. Try a smaller one.

 

Check the choke is it possible it is activated? I had an aftermarket that I forgot to switch the pilot one on. It would start and idle but would not tach out. Whenever the choke was active it would cause it to rev up but it would not idle.

 

I’m looking for a motor for a 2015 Artic Cat 550 RX. I think there’s different models that’ll fit it. Do you have any suggestions where to find one? And also some rims and tires?