Topic: After market ignition coils

[haroldhupmobile]

Cylinders 2 and 3 on my bike don't seem to be firing well compared to one and four (licked a finger and touched the exhaust pipes).  I checked and reset the gap and timing and it seems to be more of the same.  At this point I'm convinced the coil for 2 and 3 is shot.  Considering they don't come cheap and I'm trying to keep costs down, can anyone weigh in on these aftermarket coils:

http://www.jcwhitney.com/IGNITION-COILS/GP_2005149_N_111+10211+600014397_10111.jcw#BVQAWidgetID

JC Whitney's website claims they'll fit but tend to be skeptical.  So, has anyone used them, or am I better off spending the extra $30?

[Gordon]

What's convinced you it's the coil?  A problem with a corresponding pair of cylinders could indicate a coil problem, but it could also be many other things.  Replacing parts as a method of diagnosis can get very expensive and time-consuming. 

It could easily be a problem with the carbs, spark plugs, plug wires, valves, points, condensers, etc. 

[Clutch Cargo]

HH,

There are some things to check prior to condeming your old coil(s).

Do a bench check with a good Volt/Ohm meter.  (don't have the specs handy - perhaps someone else can chime in) You are looking for 5 to 7 ohms on the primary and many thousands of ohms on the secondary.

Also  - Remove the plug caps and cut about 1/2 an inch off of the end of the ignition wire. This will give you a better connection when you screw the caps back on.

...and while you have your caps off and your ohm meter out - measure the resistance of the plug caps  - you are looking for 5K to 7K ohms....  They do go bad  -  I had 20K ohms on two of my original caps.

Clutch....

[haroldhupmobile]

I am going to pull the coil and test it.  I'm pretty sure the test procedure iis in the shop manual, so that shouldn't be any big deal.  I find myself being very contingency oriented like to think ahead. The coil seemed the logical faulty part, so I thought I would ask.  Gordon mentioning the plugs led me to think that if the timing had been off then both those plugs could be fouled and that would prevent proper ignition so I'll check those before I pull the coil.

[eurban]

If your plug wires will reach, an easy thing to do is to switch the plug wires from 2&3 to 1&4 and then switch the blue and yellow wires at the coils.  If the problem now moves to the 1&4 pairs then you can be pretty certain that you have a bad coil.

[OldSchool_IsCool]

Are you using points?  If so, check the points faces for pitting.