I wouldn't go back to a mechanic who changed my pilot jet for a problem that occurs at atleast half throttle and 60 mph.

 

Well they are a Kawi dealer and the bike has not been right since day one, so as I see it, I really don't have a choice. I am more than able to work on the bike myself, but it is a warranty issue and I feel they need to resolve it one way or another. I just don't want to dig into the issue and have them come back at me and say it is something I did to cause the problem. You know how dealerships and warranty's can make things very complicated to benefit themselves and screw the consumer. They changed the pilot and adjusted the needle position last time it was there. He called yesterday and seemed to rule out jetting issues. Hopefully he will come back with something today.

 

It seems from what I'm reading on this thread that there's pretty good evidence to suggest that there may indeed be an electrical contributor, if not cause to the problem. With as many people who have re-jetted, moved needles, and replaced carbs only to have the problem persist, I can't help but suspect something in the electrical system/ignition. I eagerly await your research on the issue, as I'm not technically savvy enough to do it myself. If this turns out to be a widespread problem, maybe we can get Kawasaki to do a recall and fix it.

 

My bike does this also. Sometimes more than others but no matter what above 60mph it happens.

 

The problem sounds pretty wide spread. Plenty here have remarked of it. Before Kaw can do a recall, they need to figure out the problem, and from what I can deduce reading all the threads, they haven't narrowed it down yet.

Makes me glad I have an '06. I don't think the problem is reported much for that year, and my bike doesn't do it. Must be frustrating, to say the least. I hope someone figures it out soon.

 

Today's results:

We hooked up the scope to the secondary ignition. Directly to the coil wire.

The bike was running fine till it got warmed up then missed a few. I tapped my son's knee to hit the stop recording button. He said it went blank. (batteries died)

Once we got back, I plugged the thing in and reviewed the last 40 screens. Time was set at 20 ms. Should have been 50ms and I had the max KV at 8 which was not enough.

Most of the plug fires took about 6k to 8kv to initiate the spark, then the spark itself was around 1 Kv. Other times initiation took over 8kv by a lot and the spark ran at 4kv to 6kv which is high for most anything. This could be caused by a lean condition or many other factors, so today I have no conclusion, but at least a little information. Next time I will expand the overall voltage to 20Kv and slow the time a little so I can see the whole duration of the spark on the screen. I will also try primary ignition on the negative side of the coil. This will tell me a little more.

Picture this, Dad on the bike, 19 year old son, 2 wires going to the spark plug wire and son holding an instrument the size of a clipboard flying down the road turning 7 to 9 grand waiting for it to screw up. Speed was 45 to 70 mph. It will do it in the lower gears, but seems to be best under a light or medium load.

David

 

Just make sure you keep your eyes on the road!!!

 

I had the same problem and never got it fixed... The dealer started by blaming the gas with water then the jetting then replaced the wiring harness... And the issue still persists... I fighted for 5months over this issue and nothing was fixed...

The only fix that worked was to trade-in the bike for another brand (Aprilia Dorsoduro)...

There was a thread going on that shows all the efforts I made to try to find the problem:
https://www.kawasakiforums.com/forum...et-coil-34783/

Instead of riding the bike down the road, try the following:
- Neutral on bike stand; Rev the bike to a steady 6500RPM and keep it there (you should get the surge)
- Now unplugg the Voltage regulator and do the same... You should not have the surge anymore...

David, I just realized it was you writting this and I jump to conclusion... But I know you are more than aware of the problem I had... Sorry...
Now figure out where the problem is... And let us know...

 

David, any more progress with the scope? That seemed to be a very promising lead.

 

Yes, I bought a new battery pack for the scope. It will now run 3 hours instead of a few minutes on duracell C batteries. I am not done. I am going to unhook the reg/rectifier next time and see what it looks like.

David