To review: I am working on a vintage Evinrude 70hp outboard motor which has not been started in over a year. I had the American Bosch starter repaired (it did need it, thanks!) but the motor still will not turn fast enough to turn over. It does turn without the plugs installed, but as soon as I put them in, and try to turn the key, the engine does not turn fast enough to start.
What is the next step?
br549
Favorite Answer
Charge the battery
jtexas
doesn't take that much battery to start that motor.
Assuming the battery's good and fully charged, how convinced are you that it's a cranking RPM issue? It only takes about 250 RPM's (assuming 1972 or later magneto-driven CD ignition).
45 auto
Replace the cables & new battery> If still not working the start has a bad ameture>
wicky
you will need a new, higher cranking amp battery - there usually is a number on the battery - 550 ie is 550 cranking amps - bump it up to 700ish and see what happens