kx 250 with noises ...

[alaskamx]

So this one is killing me! My 05 kx250 is all stock. It starts making this noise about half way through the motos. It is a rattly noise, sounds like its coming from the left side engine case. Plugs look good. I run 50/50 trick race fuel and good synthetic oil. I thought it was my chain guides (which were worn into the swingarm) I changed them, noise is still there. I went fatter on the main (from 160 to 162) but have the needle in the lowest position (clip at the top). One more thing, I have broken 2 return springs on the power valve assembly. I'm on the 3rd one, and would bet it is now broken too. Maybe the power valve is rattling? It never makes the noise at idle or even medium speeds. I have to be pinning it for a few laps, and then as I rev out the gears, in 3rd and 4th, it makes this godawful sound. It is worse than pinging, but could be pinging I guess. I replaced the top end 5 days ago. The old piston looked so good I feld dumb for replacing it. I think it's either pinging, the chain rattling somehow, or the powervalve. Anyone have a clue? :bang:

 

[Britt Boyette]

I would check the power valve first but if it's pinging, I would try either rejetting or race gas or both.

 

[alaskamx]

has anyone ever heard of the power valve rattling loud enough to sound like pinging at full throttle?

 

[alaskamx]

power valve spring was good.
dropped clip one spot and went from a 162 to 165 main. plug appeared light tan, although you have to have a hacksaw around here to read a plug..

 

[kawamaha]

look what i did with my power valve spring:

http://www.supercross-online.de/e/

go to tech, then KX250 '05

 

[alaskamx]

did you notice any wierd noises when the power valve was broken?

 

[alaskamx]

so it is still pinging, i think. it only does it when the bike is ran very hard, and only on long, sandy uphills and straits. sound like pinging? I'm going to raise the needle and try again. running 50/50 race gas. stock motor. 162 main. 50 pilot. needle in 2nd position from top, (now)
power valve spring was not broken.
it is cooling off from summer here. must be pinging.
plug still looks light tan.

 

[AST]

its pinging from your needle..Thing drove me nuts.I had a guy with a few 05 kx 250s tell me that the stock needle is too rich but lean in a spot that causes pinging.Mine would make a popping noise almost like a small backfire.I tried lots of different jetting- mainly changing the main.It still popped no matter what I did.I bought the jd jetting kit and the bike runs great.It stopped some of the ping but not all of it.The bike only pops climbing a hill or exiting a turn in deep loam.I guess the fix is the following. Purchase the stock 04 kx250 needle (which is a NALF)clip #2 , main 165. He said the 04 needle solves the pops. I purchased one for $18 and plan to try it out this weekend. I will post again to let you know results.

 

[alaskamx]

you are right!!!
it was the jetting. i snagged a needle from my 04 and fattened up to a 165, and no more nasty sounds!
Thanks.
This is a great board.

 

[Bad _Ant]

According to a Australian Team Kawasaki mechanic, the '05 has a "wild ignition curve in them standard" and detonation (pinging) is also fixable by retarding the timing one mark.. obviously not a complete fix if the jettings way out too! ;)

I also found low octane fuel to be a big recipe for the ping..:think:

Does the '04 needle make it nice and crisp on the right clip? No rich/lean spots anywhere? I know that Kawasaki mechanic manufactured their needles specially and hoped to release them for the public but an '04 needle will be heaps easier to get hold of! :nod:

 

[AST]

the 04 needle(nalf) is much better than the 05 needle..I ran it(04) on the second clip and it was slightly rich down low.It was still not as rich as running the 05 in the stock position(#2). I still had a couple of pops (nothing like it was doing) so I tried moving the clip to the 3rd position.Third position the bike was realy rich down low.Once it was past the rich point,it would pull hard and clean. I then tried going back to the stock needle because I had been running the jd needle before I tried the 04 needle.I put the 05 needle on the stock position(2) and took off.The bike is way rich down low and when I started riding hard,it popped like crazy...So now my next step is to try running the bike with the 04 needle on the second clip and with the timing retarded some.I tried to do this at the track but ended up stripping the stupid phillips screws out that hold the timing marks in place.Got them switched out to bolts that will be easy to adjust now.I retarded the timing a half of a mark and will give it a try this weekend. I have never retarded a bike so I dont know what to expect it to do. I just know that I dont want to lose alot of power. I have also noticed that whatever the popping sound is has caused my rubber orings on my exhaust to break. I hope the timing thing will get this pop to stop! The bikes is awesome except that noise!

 

[AST]

could you post a link on here if the kawy guy ever gets those needles for the 05 into production? I would love to have one. The 04 is much,much better than the 05 needle but it still has a slight rich spot at the start of the mid range.Thanks.

 

[Camstyn]

I noticed mine was pinging last weekend too, and I'm running straight VP C-12 with Maxima Castor 927 @ 32:1.. This was at high elevation (~4-5000ft) but it was considerably cooler weather than what I've been riding lately. I couldn't figure out what the noise was either but it sounds like what you described, time to play with the jets again I guess!

 

[kx137]

Any updates? I also run straight C-12 w/ castrol TTS @ 32:1 ... sea level, Just purchased my 2006 KX250 and finally was able to rip on it yesterday after a plethera of greasing, antiseizing, breaking in etc, etc, etc. It makes this infamous ping sound that almost sounds like a metalish ping when I am coming out of corners real hard. The bike is running real rich so I have some jetting to dink around with. Planning on going w/ the JD jetting kit / 04 needle / or this kawa guy needle. Other than this problem, I love this bike.

 

[vader 551]

kawasaki state that some 05/06 kx250,s ignition pick up is to close to the fly wheel set gap to 1mm, my local dealer has this in writing from kawasaki .