Doggies, I posted the information below to your other thread which poses the same questions you ask here . If you're going to ask for help, you need to detail EXACTLY what you've done to troubleshoot your problem. Sorry, but if several people take the time to respond to your post, then it's pretty tacky to (apparently) ignore their advice and post up the same questions.
So here is a direct question: Do you have a manual and a multimeter? If not, everyone here is wasting their time.
"Doggies, I think you are on the right track in thinking it's electrical, but you definitely need to check for spark from all four plugs. Check it when it's running good and when it's not. It's possible you have an intermittently bad coil which would show up as two plugs sparking and two not. Test in a darkened area because the spark can be hard to see.
I don't think the rectifier or the stator could be the cause of no fire, as they are only responsible for charging your battery.
Do you have a multimeter? If not, get one. Harbor freight $4 one will work fine, or go to Sears and get a $20 one. Although this very likely isn't your problem, you can check battery voltage when the bike is off (should be higher than 12.3 volts for any reasonable battery) and when it is running (approach 14.0 volts at 5k rpm). Those are the values on my bike, anyway, and are in line with what others are saying. Assuming this is ok, your reg and stator are ok.
Next you can use your multimeter to test for continuity in your switches. You will need a wiring diagram for this. If you don't have a Suzuki manual (you do have a Haynes or a Clymer though, right?) go to BikeCliff's website and download the pdf.
http://members.dslextreme.com/users/bikecliff/
It's really easy to do, and it's how I found that my starter button was bad.
You can also use the meter to measure resistence in your coils and spark plug wires. That will tell you if things are going south with them.
There is also an ignitor/cdi test described in the Clymer manual, but people have reported mixed results. I don't think I would trust it after reading the procedure.
It still may be fuel related. Are you using the original petcock? Mine was bad and I bought a new one from Z1 enterprises. Make sure your vacuum line is intact. It runs from front of the #2 carb (left to right as you are sitting on the bike) and goes to the smaller angled nipple on the petcock. When vacuum is applied, gas flows when on the "run" position. I doubt this is your problem, but anything is possible.
If any of your electrical values (resistance, continuity, voltage) are out of spec, you've likely found your problem. Searching the website will get you lots of good advice."
Bike is unpredictable. Seems like it is electrical problem. Bike will start right up when cold some days and somedays it won't fire at all,getting no spark,It may run finefor a half hour then when you shut it down for a stop nothing just cranks until the battery dies. I was told ignition coils,rectifier,ignitor box,does anyone know about this bike maybe a little better or experienced the same problems. I just put the bike on the road but not riding it too much,not many work on the older stuff. The bike has about 22k on the clock and a 4 into 1 header moves good when running. Any help would be greatly appreciated. God Bless Dave
broomall,pa. 19008