Backfire.. No start.

Just got my '79, KZ 650 SR put together. I had to replace one ignition coil, pull cable for acceleration, battery.. But now when I try to turn it over with the starter it just turns and doesn't even try to start.. When I use the kickstarter I get gray regular smoke from the 1rst and 4th cylinder, and backfire and air from the 2nd and 3rd.. (The exhaust is routed the same as the ignition coils, still stock, 2 and 3 come out of the right 1 and 4 out of the left pipe) It wont start, and I'm kind of confused... Help. Could it be the timing?
Thanks,
Ed

when you were replacing the coil, did you by chance swap the wires on the coils, kind of sounds like its wired backwards

The plug wires or the wires going to points and the power supply? Firing order is 1 and 4 2 and 3 I think I got that much right heh. I'll try swapping the wires going to points..
Thanks,
Ed

HOW do you know which coil is the 1/4 coil and which is the 2/3 coil? That is the point I think... The BLACK wire coming up from your ignition and connecting to A COIL is what makes that coil the 1/4 coil. The green wire makes the other coil the 2/3 coil. The symptoms you describe sound exactly like what would happen if you put the green wire on the coil that HAD BEEN the 1/4 coil (wires running to 1 and 4 plugs). It is generally pretty difficult to put the plug wires on the wrong plugs if they were cut the proper lengths... My 2 and 3 plug wires couldn't possibly go on the 1 and 4 plugs because they are just not long enough. They are cut these lengths to avoid the shorter cables touching the longer (1 and 4).

Sounds just like coils wired wrong. I recently bought a non-running bike and found the ONLY thing wrong with it was the coils mixed up. After fixing that issue the bike started right away and ran great!!! Good luck!!!

Ok... Had them wired backwords.. The coils I got both had black wires.... Anyway, switched the wires and it started on the second kick. Now its doin a funny thing it used to do, when I give it gas, the RPMs go up and stay for about 2-3 seconds, before returning to about 1, and then idles rough. I can start it, get it to a good sound idle at 1- 1 1/2 RPM, but if I rev it, it stays up then when comes down I have to set the idle higher or constantly give it a little gas to keep it running. Also theres gray smoke coming from the right pipe..? Thanks for all the help,
Ed

The slow return to idle may have something to do with the new cable you installed. Check to see if it's routed wrong. It could be pinched between the tank and frame. Did you lube it before you installed it? Cut the corner off a baggie, tape it to the cable , fill it with light oil.



Post edited by: OKC_Kent, at: 2007/10/18 13:29

The bracket that holds the cable on the carbs returns freely... What else could it be? I lubed it before installing.

CptEDIV wrote:

...when I give it gas, the RPMs go up and stay for about 2-3 seconds, before returning to about 1, and then idles rough. I can start it, get it to a good sound idle at 1- 1 1/2 RPM, but if I rev it, it stays up then when comes down I have to set the idle higher or constantly give it a little gas to keep it running....

Might be air intrusion at carb holder. Try spraying WD40 around carb holders while bike is idling. Intake of WD40 will result in smoke from the exhaust and likely engine stall.

P.S. -- Leak might also be from bad cap on a vacuum nipple.

Post edited by: Patton, at: 2007/10/18 14:03

Vacuum leak... Could it be a bad head gasket.. When trying to start it with the wires backwords it blew some smoke or somethin out of the air intake, under the seat once... Ok, Ill spray down the carb holder, thanks.

CptEDIV wrote:

...I'll spray down the carb holder, thanks.

Just to confirm -- the spray should be around the carb holders where the carbs are connected to the engine (not where the carbs are connected to the air-box or pods).

Post edited by: Patton, at: 2007/10/18 14:26

Ok so I spray down where the carbs go into the engine with WD 40.. What is that supposed to do..? Like dripping oil into a cylinder with bad compression..?
What do I do after that?
Thanks,
Ed