Re: mercury 90
Howdy, Tilley.
Welcome to iboats.
The most common, and easiest to fix, cause of that is bad connections of the battery cables. Take both ends of both cables loose, scrub them shiny, and reconnect. The worst offender is usually where the battery ground cable bolts to the engine block.
If that doesn't fix it, then connect jumper cables directly from the battery to the starter and engine block to see if the starter is good. No turn, bad starter. Starter works now, replace solenoid.
Good luck, and let us know how you make out.
