Ok so went back to dealer again and expressed once again to look at the coil spark and wiring area as everyone suggested here and I greatly appreciate.
Dealer called back and said Kawasaki techs want them to do more adjusting on the carb?

 

Well, from what you've told us about your issue, it is heat related, repeatable, predictable, and persistent. Nothing about the design and engineering of the KLX fuel system allows extreme heat to be absorbed by the carb,or fuel lines.- possibly creating a "vapor lock" and fuel starvation. Nothing about the carb is "heat sensing" or heat controlled. I.E. The choke is strictly manual.

Since one could assume that Kawasaki "techs" would know all this, IMO, you are not receiving the proper service from that dealer.

 

I certainly won't claim to be an all knowing mechanic by any means, and trying to diagnose your problem over the internet is difficult to say the least. However, it's been a disturbing trend in automotive, motorcycle, etc. vehicle diagnosis and repair that true mechanics capable of effective diagnosis are less frequent. Many/most have become parts changers who just attack problems with swapping parts That's especially problematic when dealing with electrical issues. Using electronic diagnostic tools and resources is often fuzzy logic to many. And honestly electrical gremlins can be challenging to anyone.

Over the internet here, we can't swear that the carb or fuel system isn't the problem, and we have no idea on the mechanic's capability in servicing the carb. Still, from just what's been presented here, it doesn't sound like the carb. What is this "adjusting" on the carb that Kawasaki wants to do? They should have laid out some specifics to the mechanic. I worked at a motorcycle shop part time for quite a few years as a mechanic, and when we had something we had to go to Kaw tech on...a rarity...they wanted to know exactly what we had done, then they gave very specific things to try or recheck.

 

I think many shops (dealers or bigger ones in particular) lack creativity in making a hypothesis and then trying to prove or disprove it. If they believe it's the carb, they should be able to explain in basic terms what they believe is happening as the bike comes up to temp that would cause an air/fuel problem. If they don't have a hypothesis they're unlikely to luck into a solution. They also tend to lack creativity in creating test rigs to make diagnostics easier.

If for example as I and other suggested it could be heat related for the coil, then there's two ways to test: introduce heat or introduce cold. While most of the heat is internal, putting an ice pack or cool water drip on a component during a test can help to identify if there's a difference in time to failure. Or using a heat gun at a safe temp and distance to prewarm a component to see if it accelerates time to failure.

 

I agree. so some spray freeze on the coil (available in electronics stores) . could also be the stator's charge and trigger coils. maybe take some volt and ohm readings before and after, the manual has numbers


edit: I'm assuming these guys are smart enough to open the gas cap to see if it is a venting problem