Stoopid Electric Problems! Arghhh! Help Please.

[bfpd630]

So I started up my 78ish 750gs after sitting all winter, and as it was running the lights got brighter and brighter and then- blam! Every bulb blew out and the bike stops running. With some help from the local Suzuki shop I guessed that the rectifier / regulator went out, causing an AC current spike. $110 for a new one. I put it in and still no spark coming from the plugwires. I talked to someone else who said that I needed a new ignitor box (the thing that tells the coils when to fire.) Well those are not cheap, but I found one that a guy took off of his bike and he told me it was still good. $150. Ouch. Did I mention that I paid $300 for the bike? So I still am getting no spark.
I need help. There are four wires going from the ignitor box to the coils, all of these have 12v when the key is on. Is that good? It seems like there must be some switching involved so I am questioning it. Could someone please help me trouble shoot this? Thanks!

[bradleymaynar]

Odds are that your R/R fried your stator. Check the stator papers found on the homepage for the procdure on how to check it.

Brad bt

[bfpd630]

would that cause a lack of spark?

[earlfor]

A faulty R/R putting out excessively high voltage (thats why your lights got brighter and brighter) will at greater than 16 volts cause the ignitor box to burn out. Installing a new R/R will solve the high voltage level problem and regulate the charging voltage to the correct level. However, the charging system is separate from the ignition system. A new R/R can do nothing for a fried ignitor box. You need to replace the ignition. Dont buy the used ignitor box for $150. It may be on its way to self destruction and at best, you're getting a 20+ year old part. For very little more money, you can buy a new Dyna S ignition that even has a warranty.

E.



quote=bfpd630;632149]So I started up my 78ish 750gs after sitting all winter, and as it was running the lights got brighter and brighter and then- blam! Every bulb blew out and the bike stops running. With some help from the local Suzuki shop I guessed that the rectifier / regulator went out, causing an AC current spike. $110 for a new one. I put it in and still no spark coming from the plugwires. I talked to someone else who said that I needed a new ignitor box (the thing that tells the coils when to fire.) Well those are not cheap, but I found one that a guy took off of his bike and he told me it was still good. $150. Ouch. Did I mention that I paid $300 for the bike? So I still am getting no spark.
I need help. There are four wires going from the ignitor box to the coils, all of these have 12v when the key is on. Is that good? It seems like there must be some switching involved so I am questioning it. Could someone please help me trouble shoot this? Thanks![/quote]

[bfpd630]

thanks- that has been helpful. I am getting 12v going into the coils, all 4 wires between the two coils are @12v with the key on. (I know next to nothing about motorcycle ignition systems remember) What does that tell those of you who know anything about this?

[bikechump]

since we have power to the coils we'll start with the easiest first. Are the plugs clean? yes? Unscrew the plug cap insert a wire and ground to head. Spark? if not work your way back. Im going to lead towards the points (im assuming is has breaker points since its a 78) Use your manual and verify that they're working. If the points don't "break" and collapse the field your not going to get spark. give us an update and we'll take it from there

[rustybronco]

thanks- that has been helpful. I am getting 12v going into the coils, all 4 wires between the two coils are @12v with the key on. (I know next to nothing about motorcycle ignition systems remember) What does that tell those of you who know anything about this?

Power goes to each coil then throught the primary winding in the coil and it comes out of the coil going to the points, if the points are closed current flows through the coil and builds up a magnetic field in the coil, when the points open this magnetic field collapses and produces the high voltage that you see at the plugs.