kx500 surging.

[Ims Roll]

My question is my k5 when i lay in to it fairly hard for more then a second or two when I go to lift the motor surges for about 5-10 seconds. like the rpm's go up and down while i'm coasting. Is this normal for a k5 or am i just paranoid? Bike has a brand new motor in it, piston, re-sleeved, fresh power valves, bottom end basket clutch ect. she's fully rebuilt. anyhow if any one has an opinion please let me know.

[Motorrad]

My question is my k5 when i lay in to it fairly hard for more then a second or two when I go to lift the motor surges for about 5-10 seconds. like the rpm's go up and down while i'm coasting. Is this normal for a k5 or am i just paranoid? Bike has a brand new motor in it, piston, re-sleeved, fresh power valves, bottom end basket clutch ect. she's fully rebuilt. anyhow if any one has an opinion please let me know.

Help me out
What's your jetting (including needle position/ type, and air screw  and altitude...


I normally shoot for 2-3 surges in my tuning

[Ims Roll]

im not home but i believe its 168 main 55 pilot not sure about air screw, stock needle (i think) needle is 3rd up (i think) and alt is about 2500ft   bike runs awesome idles perfect all around runs like a dream just the surges have me asking questions. it's probably about 2-4 surges

[Foxx4Beaver]

im not home but i believe its 168 main 55 pilot not sure about air screw, stock needle (i think) needle is 3rd up (i think) and alt is about 2500ft   bike runs awesome idles perfect all around runs like a dream just the surges have me asking questions. it's probably about 2-4 surges

Not tryin to high-jack here,or disagree with Motorrad....but if you had used the "search" option on surging,you would find a ton of info going back 10 years,stating that it's a pretty normal thing on the K5.
When I bought mine,it did the same thing pretty bad,and scary in some situations.I figured it was an air leak/running lean.I did a leak down test,and it came out good,no leaks.Played with the jetting,only made it worse.Then one day,I stumbled upon a thread on here(can't remember which one)and it said to turn the idle screw all the way out and it'll stop.So,that's what I did....and it actually helped ALOT...it still surges after a WO run,but very little compared to what it was.
I doubt you need to,but it can't hurt to do a leak down test just to be sure

[Rotorised]

Ill second turning down the idle screw.

I have turned the idle off and it surges alot less than when i had the idle up. Its a trade off but i would rather have to blip the throttle when standind still every now and then than have it lurch forward like it used to on single trails (the majority of riding we do is on single trails).

Its worth a try, only takes 2 seconds, then you can decide for yourself

[Twosmokerfan]

Mine did the same after I re-built it and couldn't get it tuned right.  It also would run great, but when I chopped the throttle after a good rev on the trail, it would rev to the moon.  Took all the connections apart on the carb, tightened everything up and it went away.  My thoughts are that I had a air leak after the slide, causing it to run lean and rev.

My jetting is very close to yours, with the exception of the n82M needle.
 
TSF

[Ims Roll]

Probably should have used the search first, wasn't thinking. i'll give the idle screw a shot and let you know next ride. thanks