Hey- my 88 xr600 recently quit running on me. A rattle in the top end (i think) developed and it died, and when i tried starting it agian it would run for a few seconds with the rattle then die again, and now it wont start up. I took the engine out, and took the head cover off and took the camshaft out. The plate (part # 6 on this diagram http://houseofmotorcycles.bikebandit.com/partsbandit/oem_schematic_view~schem_dept_id~378534~section_dept_id~1~section_dept_name~OEM+%28Stock%29+Parts~dept_type_id~2~model_dept_year~1988~model_dept_mfr~Honda~model_dept_id~375278~model_dept_name~XR600R.asp) between the decompression cam and the first cam moves back and forth very easily. Think mabye this is the source of my rattle and troubles?