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My mistake, it is a 40.5, I forgot I rounded the number out to 41. I also installed a crank out of a 1998 cr500 and installed a spacer kit to raise the height of the cylinder, huge improvement. if you can zoom in at the engine you'll see it

Ya need to install the correct spark plug in her and that is a NGK BR8EG, your carburetor is a Keihin 38PJ but I upgraded mine to a 41PWK from a KX500 and I run a NGK BR9EG plug in the winter time which is a hotter plug. No voodoo tricks, place it on a stand, choke on of course...