The Kohler system is pretty simple and thus easy to troubleshoot. I
just finished adding this system to my garden tractor (John Deere
model 208, K181 8HP engine).

1) There are permanent magnets mounted on the flywheel that are used
to excite the stator coil (generator electricity). Make sure they are
there. They sometimes come off. If this has happened, it gets pretty
messy under the flywheel. I have read that they can be re-attached
with glue, but I am not sure I would try that.

2) The typical 15 amp stator coil is an 18 pole series wound single
coil with a 2 wire output. You can use an ohm meter to verify that it
is not open (ie no broken /burned wires) or shorted to ground (likely
caused by burning or mechanical failure). The coil should read 0 ohms
between the 2 wires and infinitely between either wire and the frame
of the stator.

3) The stator connects to a rectifier/regulator assembly. Kohler uses
a very simple 3 terminal assembly. The 2 outside terminals (called AC)
connect to the stator. With the engine running, you should find
anywhere from 8 to 28 volts using a volt meter on the AC scale,
depending on the RPM of the engine (idle to 3600 RMP). Using the same
meter, switch to DC volts and measure the voltage between the middle
terminal (called B+) and the case of the assembly (ground connection).
Here you should see about 14 to 15 volts with the engine reving better
than 2,000 RPM. NOTE: Even though the assembly has only 3 terminals,
it requires 4 to operate. The fourth is the case which MUST BE
GROUNDED and thus connected to the negative of the battery. If this
connection is open, you will not charge the battery.

4) To verify that the battery is connected to the regulator properly,
stop the engine but turn the ignition switch back on. Repeat the about
DC meter test. Between the regulator's centre terminal (the B+ one)
and the case (the ground connection). You should measure 12 volts
coming from the battery. If you don't, you have an open circuit
between the regulator and your battery. You need to follow connection
from the B+ terminal on the regulator into the harness back to the
ignition switch, through that contact to the battery through the
circuit breaker.

To recap, make sure there are magnets on the flywheel, that stator
winding isn't broken, the regulator/rectifier is functioning, and it
is connected to the battery.

Best of luck!

Bob Morgoch MT (Master Tinkerer)


Stephen Kurzban wrote in message ...
Check the voltage on the battery terminals before starting,
then at cutting speed - if not higher after starting then
the charging system is either not functioning or not
charging the battery.

Possible culprits include, but are not limited to; bad
connections, defective alternator coil(s), bad diode, open
protection circuit such as fuse or breaker, current drain
such as shorted wiring.

Patch wrote:

About the only way to tell is to run it & see if the battery goes down. If
you had the right equipment you could put an ammeter in series with the
battery & see if it is charging.

"Dave" wrote in message
m...
i have 10 hp kohler engine (the engine was probably made in the mid
70's) that seems to drain the battery when the engine is running. i
replaced the rectifier but am not sure if that has fixed the problem.
any ideas?

i orginally replaced the battery, but quickly found that was not the
problem.

-david