lost my number 6 cyl fri on my 250xb ,,,motor has been great up to thst point, going to rebuild, not sure all of them or just one ,the number 6, what does everyone think. also imput on anything else to look out for . injectors ? causes ? never over heated was running about 3500 rpms when it went down, seamed like it was running out of gas $2000 for one $2800 for all