Twice this season, I've been stuck on the lake after turning off and trying to re-start my 1984/86, 70hp, 4-cyl. (in-line) Mercruiser (I/O on a 19-ft Larson bowrider). Seems to only be a problem when the engine has been operating/warmed-up, such as after cruising at 20-30 mph for 30 min or...