Kohler 3.5CM21 Generator cranks slowly, won't start

[Acuda4me]

I finally got round to hooking a (somewhat) working battery up to my 1970 Dodge Commander's generator (Kohler Model 3.5CM21) and attempting to fire it over. It cranked pretty slowly (or am I just used to Chrysler gear-reduction starters?) and wouldn't fire. Checked the spark plug, no spark at the wire. Pulled the points cover, they looked okay and they ARE opening and closing, but couldn't find a feeler guage. Then I tried tracing the plug wire back to the "coil" and couldn't for the life of me figure it out. Users manual says check for defective condenser (easy enough) and defective coil (what in the world IS it?!?!?!?). Any experts got any other suggestions.  The good news is, after some cranking, the glass thingymebob filled with fuel, so I know the fuel pump is working.

[Elandan2]

On my generator (4CM21) the engine uses a magneto ignition, usually pretty reliable.  Did you try a new plug?  I've had the best luck on many small engines just changing out the plug for a new one.  Rick

[ClydesdaleKevin]

The old Kohlers didn't use a starter, they actually used the generator as a motor to spin the engine during the start cycle, just like motor/generators on Submarines.  So yeah, they spin slower but it does the job.

My old Kohler was a 77 with the coil right on the top...looked just like an old Harley coil, and rumor has it you can substitute a Harley coil for it.  Anyhow, to find the coil, just trace the spark plug wires back to their source...they plug into the coil!  It doesn't look like an automotive coil by the way...its a rubber coated cylinder with 2 plugs coming out sideways for the spark plug wires.

Kev

[Acuda4me]

Well, yeah, I tried to trace it, but it just disappears into the bowels of the generator. Couldn't find anything that looked like a coil.

[ClydesdaleKevin]

I remember on mine the points were hidden behind the genny, and it wasn't the kind of genny where you could tilt it out or slide it out.  I had to use a mirror and a flashlight and replace and set the points looking in the mirror.  Maybe its behind the genny and you can locate it with the mirror and light trick?

And as Elandan2 pointed out, he has a similar genny to yours of around the same age.  Mine was a bright orange 1977 6k genset that used a coil.  Yours might be like his and not have a coil at all, but rather a magneto, just like a lawnmower engine.


Kev