'81 XJ550 Maxim Ignition Woes

I know for a fact I have to replace the 1-4 coil. Testing on the primary was 3.7 ohms and the secondary is infinite. The cap for 1 tested at 10.16k and 4 tested at 9.66k. The coil for 2-3 tested on the primary at 3.8 ohms, and the secondary with caps on was 22k ohms.

The problem I've encountered is the previous owner used NGK DR8EA resistor plugs. I did go through and test the spark plugs for 1 and 4 and they each tested right around 4.1k ohms. So the question I now have before I buy new Dyna 3 ohm green coils or mini coils is this. What other potential problems could I be looking at due to resistor spark plugs having been used?

 

None. Adding more resistance (via the plugs) just makes for a slightly weaker spark. It wouldn't have caused any damage.

 

That's reassuring to hear. Now I just have to focus on which plug wires, and plug caps to use to get things going again.

 

All things electrical begin 1/3 of the way down the page:

http://www.xjbikes.com/forums/index.php?threads/the-information-overload-hour.27544/

Specifics for your machine can be found here (and in the shop manual): http://www.xjbikes.com/forums/index.php?threads/xj-parts-catalog-section-d-electrical-system.44641/

Adding the year and modle of your XJ to your signature like would be helpful as there are several differences across the entire line.

 

On the 550, some trimming is required to get the dyna's to fit. The mounting bolts for the coils are at a 45° slope, and to get them to fit, you need to cut and twist the brackets flat. Some hammering of the wire harness recess is also required.

www.xjbikes.com/forums/index.php?threads/smacks-xj550-maxim-build.45723/page-2

My build thread has pics on the fitting the dynas.

 

Not sure if I made a mistake or not but I decided on the Dyna DC1-2 3 ohm mini coils for my replacements. At first I'm going to try to use the old plug wires and caps to see how things go, and with any luck I'll be able to setup a nice set of plug wires/caps while I take the time to look over the back brakes and the clutch cable I have to replace also.