Subject:RE: RE: RE: RE: RE: magneto Date:Mon Jul 31 18:18:55 2017
Response to:22178

Your research on "highly unusual for a rotor to be the
issue" is wrong. I have seen quite a few rotors that would
not start or run a motor. Even if ya use the electric
starter. What you need to find is called a magnometer or
gaussmeter. I have one. A good rotor, that makes a good
spark, measures 35 on my meter. 25 or less will not run a
motor at all. 28 and it's hard to start
What else would ya like to know about the Bendix magneto?


Does any one have a way to measure the magnetic force
required for the mag rotor? I have the rotor pulled and it
will pick up maybe 1 pound of a metal object.
Also I found a guy who is into antique tractors who may be
able to re-energize the rotor as all of the old tractors
used a magneto. He thought the rotor should be able to pick
up 10 pounds. Should have some good answers to the mag
issues when I am done.
It's official. The lighting coil in place of the ignition
coil will produce a weak intermittent spark at 1/8" (under
specs). Trying the ignition coil again I get nothing.
I am going to replace the ignition coil and re-magnetize
the mag rotor when I find the guy. There is nothing left to
replace so it has got to work.
Thanks for the help.

Thanks for the info. All my research says it is highly
unusual for the magnet to be the issue. The coil is
$90 so I hate to get it if it is not the cause. The bike
also has a lighting coil which someone said is the same as
the ignition coil even though the part numbers are
different. Tomorrow I am going to try the lighting coil in
place of the ignition coil and see if that works.
One other thing I am looking into is that in rural
Minnesota (where I live)there are a lot of antique tractors
with magnetos. I have a line on a couple of local guys who
could maybe do the re-magnetizing. I will know in a week as
next weekend there is a huge antique tractor show in
Hastings, Mn. where I live. Thanks for your input. I would
still like to know your XLCH connection info. I will let
you know how my trials are doing.
Funny connection. I am restoring this bike because it is
the same year and model as my first bike I got as a
Christmas present when I was 14. My best buddy had a 1962
Harley Sprint. We had great times and I spent many hours on
the Sprint.

I dug through my old parts and found a NOS rotor - but it's
a 29707-63R. The Hummers didn't use 297xx parts, so I
think this fits a Sprint. No help.

I would suspect the coil before the rotor. The coils in
these mags were known to be the weak link.

If I remember correctly, these magnetos were produced by
Bendix-Scintilla, who made aircraft magnetos, but also sold
flywheel mags for small equipment (snowblowers,
rototillers, etc) during the 1950s and 1960s.

I've contacted a company who re-magnetized my XLCH rotors.
They're not familiar with Hummers, so they're going to do a
little research and call me back.


62 Scatt getting closer but still a few issues.

Magneto does not appear to have sufficient magnetic force
to create the required 6 volts. Checked the ignition coil
and it passed but it could still be bad. Bike runs with a 6
volt battery bypassing the magneto entirely.
Not having any luck so far finding a place to re-energize
the magnet but I know it is done. After that if there is
still an issue it could only be the ignition coil. I
already replaced the spark coil, plug, plug wire and
Any ideas where to send the magneto for testing and repair.
I live in Minnesota but don't mind shipping it somewhere.

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