Multimeter 101/How to......ohms/resistance/contin....

[Tyler1150]

Guys,

I am working my way through figuring out why I am running on one cylinder.  Thanks to help from this forum, I have narrowed it down to pickups, coils, and or ignition module.

While I do have a basic understanding of how to test resistance/ohms...., I was wondering if someone could elaborate on testing the above three components.  Currently, I dont have the benefit of a manual either.  A walk through would help tremendously.  Hopefully others may have the same question.

Thanks! 

[Howie]

Year and model? Since you said pick ups I assume your bike has carbs.

pick-ups  100 ohms  + or -5%

coil primary (small terminal to small terminal)  later 4.5 ohms + or - 15%, earlier 3.4 ohms + or - 10%
coil secondary (coil wire tower to negative, coil removed) later 19.5K ohms + or - 20%, earlier 12K ohms + or - 10%.
I have no idea what the cut off is between early and late.  My experience with coil windings is they usually read either open or low resistance by a notable amount to cause a constant misfire.

I can give you an elaborate procedure for the ignition modules, but it doesn't seem to work to well.  The easiest check is switch the modules and see if the miss changes to the other cylinder.  If you don't know which cylinder is misfiring, it is the one with the cold exhaust pipe.  The same will work for the coils.  Do check the wiring also. Oh, the spark plug caps should be 5k ohms, + or - 10%.