No start- weak spark 550L

[Guest]

Trying to get this old girl on the road. I got it started the other day, but today it wouldn't run. Got to digging, and I have a very weak, sometimes non-existant spark. I followed the procedure in BikeCliff's website, but got stumped.
My 1980 550l does not have an ignitor??
I have one coil that is getting pretty warm upon turning the key on. I've tested everything up to that point, but got kinda stuck.

Any tips on where to go next?

Thank you!

[MatBirch]

Quick question- can I build some quick jumper wires and use my old known working honda coils to test it out??

[tom203]

Why not just play with the suzuki coils- unlikely that they are to blame. You don't have ignitor??? are you sure? contact points? Remove small round cover in front of rear brake lever and convince me.
Have you see this from Basscliff?

http://members.dslextreme.com/users/storagecliff/images/electrical_odd-n-ends.html#A17

[MatBirch]

Ok, thanks Tom!...
Found my ignitor, and I think I found the correct version of the factory manual for the submodel of the bike. Everything seems to match up. I have been working off of the BikeCliff page in your link, but I'm still having troubles. Some of which stems from apparent differences in models/years, mostly wire colors. (the instructions read to test resistance between blue and geen...). My bike has no blue... I am currently attemting to verify voltage TO the ignitor. The instructions say to check for 12V between orange/wht and black/wht. I get nothing there. I get 12V between O/W and ground though. I can't see in the wiring diagram how the black/wht would return to ground to complete a circuit??
How or where should I have 12V IN THE HARNESS for the ignitor? I'm thinking it must run through the kill switch or something?

Thanks again!

[tom203]

The O/W wire is the +12 volt feed from kill switch to both ignition coils and continues down to ignitor. On my 650 there is a 4 connector plug that connects to ignitor with the O/W wire, a B/W wire, a B/Y wire, and a W wire- the last two are the trigger wires that fire the ignition coils when the ignitor feels like it. Your 550 is likely similar but we have different ignitors- as far as I can tell the B/W wire is just a ground wire.
With tank off, and with key and kill switch "on" check for +12 volt on O/W wire at ignition coils.

[MatBirch]

Key on, I've got 12v at the O/W. Less than 10V while cranking though. I proceeded with the relay mod to not only help isolate my problem, but I know I'll want it done anyway. It did not help with my spark issue though. BTW- through all my testing I have gone from weak spark to no spark...
I have the ignitor out, but grounded solidly. Should I have a ground circuit in the plug for the ignitor? Or just the ground pigtail on the unit itself? It appears that the Bl/w in the ignitor harness should ground out, but mine doesn't. There are no switched grounds or anything right? Should I patch in a jumper to a chassis ground to further test it?

Thanks again!

[tom203]

So using that Basscliff link on ignition testing, you couldn't reach a conclusion? Weak spark ? have you removed plug caps and tested them?Sounds like you got +12 volt to ignition coils and ignitor, but you need good connections from signal coils to ignitor.

[spyug]

Weak spark can also be a result of bad spark plug caps. Overtime, they can deteriorate and resistance builds up to apoint where little to no spark gets by. Caps are around $7 a piece but well worth changing out.

I had two bad ones on one of my bike and was convinced I had bad coils. You have proven your coils are good so its either bad caps or wire with a broken core (which is unlikely).

Good luck with it.
Spyug

[MatBirch]

Thanks everyone!
I ordered new caps and wire from Z1 last night. I finally found my spark last night, although it's real weak still. I added a chassis ground to the ignitor harness, as I wasn't getting anything in the black/wht wire, either to ground, or to the rest of the harness bl/wht. That got me that little bit of spark.
I'll report back after I get the caps and wires changed out.

[MatBirch]

OK, so after all my reading and following all of the instructions I get from you guys, I got it running, and actually took it out for a little shake-down run today!
I replaced the spark plug caps, after trimming the wires back, new plugs, cleaned all connections, coil relay mod... Fired right up!

Thanks gang! On to other topics on other forums