I have a model year 2020 Kawasaki KLX 230. When I first start out, everything works just fine. But after riding for about an hour, it develops this strange behavior: when the throttle is closed, it will not idle. If I am stopped at a red light and try to idle, the engine just dies. Sometimes even when I am just changing gears, the engine dies when I back off on the throttle, and restarts when I release the clutch in the new gear. If I am going downhill using engine braking to keep speed under control, it makes a strange noise that I used to think might be backfiring, but now I suspect it is the engine actually dying but the momentum of the bike is just turning the dead engine. As soon as I give it any throttle at all, everything sounds normal. I am a brand-new rider so generally keep speed below 40 mph. I have the shop manual and the first recommendation there was to clean the air filter. I did that and at first it seemed to help, took longer for the idle problem to develop but eventually it did come back. Has anybody else run into this? Anybody have any suggestions? Thanks.
I want to add a little more information, some of this may be obvious to more experienced riders>>> This bike is fuel injected, so there is no Idle mixture screw or idle speed adjustment in the linkage like you would have on a carb. The manual specifies that idle RPM should be "1 800 RPM + or - 50 RPM." That's right, "1 800". the space puzzles me, I assume that means 1,800......can anybody confirm that? It seems high to me, no other vehicle I own idles that high, but I am new to motorcycles. And this bike has no tachometer, so I don't know how to measure the RPMs. Any suggestions?