Another heads up that happened to me on my 140 Evinrude is that a single coil packs potting had a crack behind the pack (so you couldn't see it). When everything heated up, it would short thru the pack to the block and I'd lose power. Once it cooled again, it worked for a while. It was a bear to trouble shoot and we eventually used a timing gun while running at higher speeds to look for a cylinder with spark loss. The gun helped us ID the issue and once we replaced the P-Pack, all was well again.
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