Ok so here is the story. My buddy bought a 2004 pro x 440 with a 600 ves motor I believe It is from a 2000 xc from the extra parts that came with it all gen 2 stuff. He got it guy said it needed carb work or something never ran right motor made bad noises tore it apart replaced pistons and outer crank bearings now noises are gone but it won't run right like its stuck in limp mode can't get it to rev over 6000 rpm on stand off it is a turd barely moves. Replaced exhaust valves since it had 2 different ones on it, tested stator, Cdi, coil, temp sensor all ok. Timing is at 23 btdc with tps unplugged with plugged in its at like 12 checked with timing light. Runs the same whether tps is plugged in or not. Unhooked lighting circuit to check for draw no change in rpm. Clutching is my thought but they both appear to work as they should red epi primary 58 weights yellow secondary spring unsure of brand and helix. Im wondering if the absence of the key with the premium control is making a difference in it somehow. The Cdi is correct for the 600. I'm stumped and looking for any guidance any one who has done the swap before or who is just generally smarter about this than I am May have for me. Thanks in advance for any help.