2001 kx 500 jetting need help please?

[bainzey105]

Hi I have a 2001 kx 500 im running a pro circuit plat 2 pipe with a 304 silencer, v force reeds and a k and n air filter, im running a 170 58 air screw 1.75 turns out needle postion 3rd. This setup is wat it ses on the pro circuit website.... but its just not idling right wen it sounds like it idleing okayish, il pull back the throttle and the revs will stay up to long and it will idle to high once again, there are no leaks cracks or leaks. Ive also got a 180, 175, 165 50, 62. any help will be most apreticated. Thanks  luke

[Foxx4Beaver]

welcome to the site Luke...

Are you running the stock carb?
What elevation are you at?
A 58 pilot is rather big if you're running the stock carb!, I would throw the 55 in there to start, and it's possible you might have to go down to the 52, especially if you do a lot of slow trails.
How does the plug look?...have you tried doing any wide open throttle plug chops?
You say there is no leaks, but have you actually confirmed this with a leak down test?
What happens when you turn the idle screw?

[Foxx4Beaver]

I've also found the Pro Circuit guide to be in-accurate.

the starting point the majority of us use is...

168....main
55...pilot
clip in 3rd position
1 1/2 out on air screw

then you can fine tune it from there.

[Twosmokerfan]

Hey Mate,

I agree with Foxx. Start with those settings and adjust. I had a similar problem and ended up settling on a 165 main, and went all the way down to a 50 pilot and settled on a 52 for a smooth idle. Playing with the mid range, leaning off the N82m needle wasn't enough. Playing with a n82p and slowly leaning it off. Lots of testing to do as even with the p needle, chops and trail riding at 1/4 to 3/8 throttle still gives me a pitch black plug.

But at least it isn't going though 1 plug every hour like it used to.

On the plus side, it has heaps more power now too

TSF

[Foxx4Beaver]

leaning off the N82m needle wasn't enough. Playing with a n82p and slowly leaning it off.

good point on the needle options TSF...I ended up having to go even a touch leaner, with a N82T needle, clip in 2nd from top, to clean mine up.

[Twosmokerfan]

Another point to consider,

I had jetting problems so bad I was willing to sell it and give up. I had the n82m needle and still couldn't get it to run correctly. Tried everything. Read the jetting thread like 20 times. Eventually bought a new carb with new needles and jets and started there.

Ended up being a worn emulsion tube that the needle goes into. No matter what I did with needles or jets, the fuel was never going to be metered correctly.

No it is good and I am happier, with still some tuning left to do.