Cold Cylinder #2, '81 KZ750 LTD

SnyperX wrote:

84_GPz750 wrote:

@SnyperX I just found this thread but have and am still having all of the exact same issues you describe here with my GPz750. Cold cylinder #2, hanging revs once I was finally able to get it to start and idle, charging issues, and currently I'm fighting poor running just off idle. 

I'll be keeping a close eye to your progress to see if you find a resolution that I can apply as well. 

For my hanging revs, I found a combination of the throttle cable binding up and not fully returning, and the angle of the throttle cable holder bracket needed tweaked. 

Best of luck on your project!


 

I am going to get back at this tonight. Going to pull the carbs again and check that all the o-rings are seated correctly. Hopefully it's just a carb assembly issue after I cleaned them again because of the cold #2.

SnyperX wrote:

SnyperX wrote:

84_GPz750 wrote:

@SnyperX I just found this thread but have and am still having all of the exact same issues you describe here with my GPz750. Cold cylinder #2, hanging revs once I was finally able to get it to start and idle, charging issues, and currently I'm fighting poor running just off idle. 

I'll be keeping a close eye to your progress to see if you find a resolution that I can apply as well. 

For my hanging revs, I found a combination of the throttle cable binding up and not fully returning, and the angle of the throttle cable holder bracket needed tweaked. 

Best of luck on your project!



 

I am going to get back at this tonight. Going to pull the carbs again and check that all the o-rings are seated correctly. Hopefully it's just a carb assembly issue after I cleaned them again because of the cold #2.

Pulled the carbs tonight and went ver them Checked the float bowl gaskets and as well as the float needle diaphragm (?) gaskets on the other side. All looked fine and screws were all tight. Reinstalled the carbs and attempted to start and now cylinders 2 and 3 were cold and seemed to not be firing. So frustrated at this point. Just wanted to have the bike running decent by Spring and its been nothing but a cluster so far........ I had it running decent for a couple days and that has been it since owning the bike for almost a year now.

Wookie58 wrote:

SnyperX wrote:

SnyperX wrote:

84_GPz750 wrote:

@SnyperX I just found this thread but have and am still having all of the exact same issues you describe here with my GPz750. Cold cylinder #2, hanging revs once I was finally able to get it to start and idle, charging issues, and currently I'm fighting poor running just off idle. 

I'll be keeping a close eye to your progress to see if you find a resolution that I can apply as well. 

For my hanging revs, I found a combination of the throttle cable binding up and not fully returning, and the angle of the throttle cable holder bracket needed tweaked. 

Best of luck on your project!





 

I am going to get back at this tonight. Going to pull the carbs again and check that all the o-rings are seated correctly. Hopefully it's just a carb assembly issue after I cleaned them again because of the cold #2.

Pulled the carbs tonight and went ver them Checked the float bowl gaskets and as well as the float needle diaphragm (?) gaskets on the other side. All looked fine and screws were all tight. Reinstalled the carbs and attempted to start and now cylinders 2 and 3 were cold and seemed to not be firing. So frustrated at this point. Just wanted to have the bike running decent by Spring and its been nothing but a cluster so far........ I had it running decent for a couple days and that has been it since owning the bike for almost a year now.

#2 & #3 share the same ignition coil so your issue may be related to that rather than fuel (did you consider Nessism's kind offer ref your carbs ?)

Nessism wrote:

Coils rarely fail.  Sometimes the plug caps do, or the wires can gain resistance at the contact points.  If you lay a spark plug against the engine, and you can see a reasonable spark out of each plug, you are most likely fine in that regard.

Nessism wrote:

Open the drain screws on 2 & 3, and make sure the bowls are full?  

• Air
• Fuel
• Compression
• Spark

Nessism wrote:

Not sure what to suggest, grasping at straws.

When in doubt, go back to basics.

Compression: you need at least 100 psi per cylinder.  100 is low, but it should be enough to fire the cylinder.  Cam timing needs to be correct.  Double check.

Spark: Spark doesn't need to be overly strong, but it needs to be there, and at the proper timing.  Your bike has Kawasaki's excellent electronic ignition.  If you see a spark when grounding the plug, as you have mentioned, that should be good enough to make each cylinder fire.

Carbs:  From everything you have said, these are clean.  

But where does that leave us?  Everything is fine?  Apparently, not.  Something in the above areas is causing a problem.  From where we sit here, we can't help you much.  Something with the basics must be causing a problem.