Our sailboat is powered by a 1994
Yanmar 4JH2E with 2880 hours on it. We have owned the
boat since new. The
engine runs flawlessly and starts in an instant if the starter spins.
At times, when I turn the key, I just get a click from the solenoid and the voltage on the 12V lead to the solenoid drops from 13.8V to 8.8V. The click and no starter spin began occurring, very infrequently about 100-engine hours ago, prior to replacing the starter/solenoid and key switch and has become more frequent in the last 18-months.
I made a small jumper with a switch in it to connect the
battery lead to the solenoid lead (a safer version of the screwdriver trick). I get the same result when I turn on the switch: Ten times in a row the starter spins the
engine. Then I get the “click” and no starter spin. That might happen just once or several times in a row. Eventually, the starter spins when I re-activate the switch.
In the last year, as a matter of preventative
maintenance, I have installed (20-engine hours ago) a new OEM starter and solenoid, B-panel key switch, cleaned all starter circuit connections, and put new ring connectors on all wires. I have verified 0 (zero) ohms resistance in all the
wiring from the key to both leads on the solenoid. The problem is now occurring quite frequently.
I imagine the problem is a bad tooth, or tooth with a burr, on the flywheel (ring
gear in
Yanmar terminology). The starter pinion
gear hits the burr and can’t advance, thus the starter
motor can’t be energized.
A common problem in the older cars I have worked on!
I have to remove the Yanmar
alternator,
exhaust elbow, and
exhaust manifold (heat exchanger) to get to the starter and flywheel. I do not want to bother with all that
work if there is little likelihood of being able to fix the bad tooth.
QUESTION:
Has anyone bothered to remove the starter from their Yanmar and mechanically rotate the engine while trying to find the bad tooth or burr?
Did you successfully smooth the tooth or burr?
Any other comments on the cause of the problem?