Re: champion blue ribbon coils

[David Stanton]

The model number is often stamped into the side of the transom clamp assembly and may be painted over but still legible. It will likely be a number and a letter, like 1J, 1K, 4K, etc, but some have more characters, like the Hydrodrive units where model may be a format like 4LHD. Like Frank said, some never need an impeller if it is aluminum.
Dave