1976 GT500 no power at coil

[bbillington]

Greetings, folks

A google search led me to this board and I've dug around a bit but haven't quite figured out the best route for figuring out a scenario where I have no power to the coil.

key in the on position, kill switch in run. good battery. bike has a new CDI on it installed by previous owner. I should be seeing 12V when I try to read the + side of the coil, right?

I did manage to get it running briefly at one point, but haven't been able to since. Fuse is good. Grounds are all rough and will need replacing. Any threads I found here that related to this issue were for the points bikes rather than PEI system. If this has been run through before, I apologize, but could use a bit of assistance if you folks would be so kind.

Much obliged
Bryan

[jabcb]

Did you just get the bike from the prior owner or was it previously working just fine for you?

T500 wiring diagram, which has points: http://home1.stofanet.dk/optik/suzuki/t500eldiagb.htm

GT500 has PEI and modifies this wiring with: http://home1.stofanet.dk/optik/suzuki/gt500eldiagb.htm

More wiring diagrams are listed in this forum under Electrical - Wiring diagrams.

Take a look at the GT500 wiring diagram. PEI is completely separate from the bike electrical system.
There won't be any measurable voltages in PEI unless the engine is spinning.

Check the plugs.
What condition are they in? Did you try new plugs?
Are they wet? If so, could be a fuel/carb problem.

Pull the left plug & ground it to the cylinger head.
Both plugs fire at the same time, so keep the right plug installed.
When you kick start the bike, do you get a spark?

Bad ground or dirty connector in the PEI wiring could stop it from sparking.

For info on diagnosing PEI take a look at: http://home1.stofanet.dk/optik/suzuki/index-3gb.htm

Also take look at Suzuki service bulletins.
Service Bulletin GT-28: http://www.ozebook.com/compendium/techb ... 027-33.pdf
Specification-6: http://www.ozebook.com/compendium/techb ... %206-9.pdf

[bbillington]

It was non-running when I brought it home, but I did have it running, albeit briefly.

Thanks much for the links and tips. Much obliged. I'll report back. I'm looking forward to delving deeper into the wealth of knowledge here and getting more familiar w/ these fascinating bikes. My first two stroke.

Thanks again

[tz375]

As jabcb pointed out, that bike has a CDI ignition which is not part of the usual 12v system. It has its own charge and trigger coils to fire off the ignition. It is important to clean those ground leads though.

I'd start at the other end and replace the plugs with a new pair and then turn your attention to the fuel supply. Drain and clean the tank and clean the petcock and fuel lines and then strip and clean the carbs.

[bbillington]

Thanks again for your help. The tank and petcock are certainly suspect. PO did a really bad KREEM job and there are pinhole leaks on the tank and the petcock definitely needs a rebuild.