update:

Q4 slip-on installed. DJ140/2N done per Klxster's recipe. Air/fuel screw 2.5 turns out. Airbox lid removed. Smog stuff removed. Idles at 1300 RPM.

Impressions:

Starts easier. Needs less choke time. More power, but it won't power wheelie. Much louder. I may invest in the quiet insert.

I do notice some popping on deceleration when I close the throttle abruptly at above 9K RPMS and the RPMs lower between 6K to 4K. The popping stops as the RPMs lower past 4K.

Any suggestions how to limit this popping on deceleration?

Thanks

 

Probably an air leak at the joint from your slip on. Did you use high temp sealant and allow it to set for 24-hours before firing it up?

 

First make sure all the exhaust connections and seals are tight and leak free and that the smog nipples , one on the intake manifold and one on the head, are properly capped and not leaking.

With that done - decel fueling is via the pilot circuitry. You must richen this circuit on our KLX's in order to kill the pops. Turn the fuel screw 3.5 out from lightly seated, readjust the butterfly valve to return idle to 1300 (if need be)... That should "fix" it..


The bike should power wheelie - You will be using a higher starting speed than what you see in my video as you are not running the MCM. Test by increasing your starting speed in 1MPH increments. I'd start the process at 15mph (with your 13T primary spraughkit). You'll find a point where the TRQ ramps up the hardest.. A lot of this has to do with your body mass - my kids can't get my KLX to wheelie like I can - I'm 6'1" 220lbs, mostly in upper body.. Queen of Spades just posted that she is getting power wheelies now with her Q4 on, and a much milder CKV/Airbox configuration than you have.

 

Everything checks out. No exhaust leaks. No vacuum leaks. 3.5 turns out. idle set to 1300.

but still popping between 5K and 4K during engine decceleration. is some popping normal? or are my expectations unrealistic?

 

Well crap. Don't tell me - your at sea level.. The stock #35 pilot jet is hard pressed to fuel decel on uncorked bikes near or at sea level. Order a #40 pilot (Kawa #92064-1108)..

While waiting, you can try a reset of the idle butterfly to 1500RPM - maybe that'll allow a little more draw through the pilot systems' transition holes..

FYI - the pilot system transition holes lie on the floor of the carb barrel between the butterfly valve and the slide, to be precise, just behind the butterfly. They are NOT controlled by any screw or valve like the idle port is (with the fuel screw). They are tiny and they flow when there is high vacuum between the butterfly and the slide.

 

I'm not at sea level. I'm at 40 feet. Big difference. My basement is dry when it rains!

My apologies for not mentioning my elevation. I thought I did.

 

I just updated my profile

 

and my signature

 

For the readers - He did reset to 1500 RPM and his decel pops did diminish even more.

 

As I said, crack the throttle open a bit, done in this case by setting up the idle which will slightly open the slide a bit, reduces the light misfiring. The decel popping is not an issue, pretty much normal. Want to eliminate it, set the idle up around 2 grand, but it's gonna rev at that higher idle while sitting still.

Cracking the throttle or setting the idle higher allows a slight draw of additional fuel/air mix in to allow regular fuel ignition instead of an extremely lean mix that will not fire every time, then when firing may be delayed and ending up firing while the exhaust valve is opening.

Some new bikes will do the same thing, you just don't hear it quite as much with all the exhaust closed in by double wall tubing or fairings and much larger mufflers. Riders will ask about a kind of metallic rattling in the mufflers. Stock bikes, has happened for decades.

Never been anything big. Heck Harley riders kind of revel in the light popping when they close the throttle.