TOPIC:

Hello there everyone, I’m new to the forum. I’ve owed a 1979 KZ1300 for the
past 5-6 years, it’s been sitting in storage most of the time, Beautiful bike! I love it.

Last week I wanted to take it out for a ride, cleaned the carbs, put a new
battery, changed the oil.. etc, and went on a ride, the bike was running great.

Took it out again yesterday and for some reason the bike was running really rough, it was running
on only three cylinders, 2,3,and 4. At first I thought it was a carb issue, then I checked the spark
on the cold cylinders, took the plug out and checked if there is a spark…. No spark.

I have this tool that checks for spark (a small clear plastic tool that you put between
the plug and the plug cap) and it shows that there is spark, I tired a new plug then thinking
maybe the plug fouled, still no spark. I’m lost… would appreciate any help. Thanks, Ron.

First, Welcome to the site !!
That's 1 beautiful looking 1300. Love the paint. I can see the metalflake down below. Must be hard to look at in the bright sunlight. The rest of the bike looks spectacular.

So on to your problem it runs on 2,3, and 4 and not on 1,5 and 6. Hmmmmm...
1 and 6 are on the same coil so that could be a coil issue but usually the coil issues show up when hot and subside when cool. I would still look at the 1-6 coil and see if it has a crack down the side of the coil. (May as well check out the other coils while you're down there. And for shits and giggles, check for voltage coming off of the ballast resistor going to the 3 coils just to confirm that the ballast resistor is ok. (Probably is, but just good to know.)

2 and 5 are on the same coil but it's running on 2 and not on 5? First I'd switch the plug out on 5 with a good (known to be good) plug and see what happens. If no better, swap the spark plug wires between 2 and 5 and see if 5 is now running. That will eliminate a problem with the coil wire and spark plug cap.

Start with that and see where it leads you.

KB

Will do, i'll try to work on it tomorrow, will report back....
thank you.

Ron wrote "I have this tool that checks for spark (a small clear plastic tool that you put between
the plug and the plug cap) and it shows that there is spark, I tired a new plug then thinking
maybe the plug fouled, still no spark. I’m lost… would appreciate any help. Thanks, Ron. kz1300.JPG"

Does this "tool" look like this?



If so, that will show if a spark is being generated, flowing down the spark plug wire , jumping the gap in the tool and having a pathway to ground. That indication will show even with an oil fouled plug because the plug is now shorted to ground completing the circuit. The tool will not tell you if the spark plug is shorted and oil fouled. if it ran the day before and then dies on 3 cylinders when you started it up the next day, there's a strong possibility that some of the plugs oil fouled
If in fact you suffer from oil fouled plugs overnight, then you have valve stem seals not doing their job. There is a way to change them out without having to remove the cylinder head and there is a write up on this by Scotch.

Yes, this is the tool i have.
So how would you explain a new plug not sparking? ( and the tool shows that there is a spark)
and yes, i do get some white smoke till the engine gets warm, i might have replace the valve stem seals as some point, i have a set ready to be installed.

ronlander wrote: Yes, this is the tool i have.
So how would you explain a new plug not sparking? ( and the tool shows that there is a spark)
and yes, i do get some white smoke till the engine gets warm, i might have replace the valve stem seals as some point, i have a set ready to be installed.

So this is a shot in the dark here. On a wasted spark system, the spark travels down one of the spark plug wires to the plug, then across the spark plug gap and to ground, then across ground (cylinder head/block etc) and then jumps the gap on the other spark plug of the same coil and back to the ignition coil to complete the circuit. So that being said, did you by chance have the "other" plug wire for that coil off of the other spark plug spark plug when you did your test? ie. testing the new plug on cylinder #5 plug wire and at the same time have the spark plug wire off for #2 spark plug.

What I'm trying to explain here is the basic wasted spark system and there's lots of info on the web about it.