1981 GS550T Cylinder 2 and 3 plugs not firing

[heater63]

I recently bought an 81 GS550T. I haven't been able to start it. I found that the the plugs on cylinder 2 and cylinder 3 were not firing. I tried connecting the plugs to the left coil that normalls goes to cylinders 1 and 4 and they worked fine. So i'm suspecting that the right coil is bad. I verified that the signal generator had the correct resistance values (as stated in the Clymer manual). However, when I tried verifying that the ignitor module was working (also using the procedure described in the Clymer manual), I didn't get any of the plugs to spark. I admit though, that I'm not positive I performed the test right, since I figured I get a spark out of cylinder 4 since that coil is good.
My question is, if one of the coils works fine, does that mean the ignitor is working properly, and the one coil just needs to be replaced?
Also, what voltage should I be going to the coils? I'm currently reading about 8V exactly. Does that seem right?
Is there anything else I can try to verify whether the ignitor is truly to blame or if its just a bad coil?
I've read on some of the other threads that most people suggest going to the Dyna Ignition system. Can my bike use the Dyna S Ignition?
Thanks for your help.

[BassCliff]

Greetings and Salutations!!

Hi Mr. heater63,

It is rare but, yes, a coil can go bad. First check to make sure that coil is getting 12 volts. Check the resistance on the primary and secondary of the coil. There are other troubleshooting tips in the electrical section of my little website. The Dyna S ignition is a popular replacement/upgrade and is cheaper than sourcing a new igniter.

Now let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff