I knew my 9.9 had a rust stain in the same spot for a few years so decided it might be wise to check on it to prevent any mid summer downtime to fix something that should be fixed now. This is what I found. Luckily I have an identical 9.9 spare (the big block 9.9 that is also the 15hp) The spare armature cover was almost perfect...just the start of a small area or surface pitting...so sand blasted it, painted and clear coated it. I switched out the entire tilt trim assembly from one motor to the other. Now I need to find another cover so I can have a complete spare 9.9 again.