Topica Loopframe_Guzzi Archive


Subject: Re: coil question

Author: Bruce Giller

Date: Mar 28, 2003, 11:58 AM

Post ID: 1712420791


Chris,
To test if you are getting spark from the coil:

- remove the distributor cap and rotate engine until the points are closed
- pull center wire from coil out of the distrib. cap
- turn key to 'On' position but do not engage starter
- hold coil center wire about 1/4" from a ground and open/close points
by hand
- should get a spark at the wire

A blue spark indicates a strong spark, yellow indicates a weak one. If
blue, then look at the plug wires out of the cap. Are they old ones?
What about the age of your plugs? Plug connectors are supposed to have
5k ohms. Sometimes if you cut off about 1/2" of the plug wire the plug
end and then screw the plug connector back on helps.

If you get no spark, then check all electrical connections between the
coil, battery and distributor. And if the coil is bad, the replacement
of choice is a Bosch Blue coil (old VWs like them as well) which can be
obtained at just about any parts place dealing with foreign cars.

Pretty rare that coils go bad, I'd suspect the condenser first. A
positive test is to see if the wire out of the condenser is not shorted
to its metal shell. A simple continuity test will do. But sometimes it
tests ok but still not work. Substitute another condenser.

Bruce

'72 Eldo

Chris Berry wrote:
 
When testing a coil with an ohmmeter, I assume you hook it
between the + and - terminals and not the high voltage
terminal and one of the others, correct? Also, can a coil
be bad and still test good? I'm reading just under 4 ohms
between the terminals and have power to the coil but I'm
still not getting any fire to the plugs.
TIA!
Chris Berry
1974 Eldo Civilian (for sale)

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