Can't get an idle... Looking for ideas

[axel-moto]

Hello friends,

I have been working on Jetting a new to me 2001 KDX200 and I am having trouble getting the bike to idle. I'll post below more info on jetting and what I have tried so far - looking for ideas or stuff I may have missed.

The Bike:
2001 KDX 200
Stock bore, Steel Sleeve
Airbox Snorkel Removed, new air filter
Stock Reeds, in good shape (no light/ curling/ carbon)
Gnarly Exhaust

The Carb: original beat to hell PWK 35 (as in, looks pretty scratched up inside and out).

Current Jetting (for sea level):

Pilot 45, Main 165, Red JD needle 3rd clip, 5th slide, Air Screw 1 3/4 out.
Float set at 16mm by using the "blow in the tube and set where it seats" method.

Bike will fire up with the the throttle cracked and keep running as long as the throttle is cracked. It will run through the gears and pull decently through the rev range. Feels a bit rich and down on power, but runs. However, it will not idle.

What I have tried so far:
The bike came with the following jetting the PO claimed worked at 3000ft. It bogged pretty bad under throttle until the last 80% and didn't feel right at all, but it idled:
Pilot 45, Main 150, Stock Needle 3rd clip.

- I took the carb apart, cleaned it with compressed air and carb cleaner
- Replaced the Jet Block o-ring
- Tried original JD suggestion of 42/165 4th clip and didn't idle either.
- Checked carb boots and no cracks or damage. Ring clamps working well and tight.
- Blocked off part of the airbox to make sure it wasn't leaning out, didn't make a difference. Tried with no air filter to check for too rich, also didn't make a difference.
- Mixture screw in either direction doesn't help.
- Idle screw doesn't seem to do much to the idle but I checked that it indeed is raising the slide.
- Jets are all Keihin branded, both 42 45 and 165 are new.
- I set the float height twice, once using the version in the manual (carb horizontal and measuring from base) and then another time by blowing in the gas tube and setting the height at where it was sealing.

Additional random info:
- Plug looks wet from gas but not carbon fouled.
- The PO had a inline fuel filter but was using very slim tubing, I replace with a direct line of correct diameter.
- Checked compression, solid 150 every time
- Changed throttle cable (I don't think this has to do with anything on this bike but you never know).
- The carb overall looks pretty beat up and I'm seriously considering getting a lectron, especially given that I will be riding this at wildly different altitudes (one of my spots is sea level, another is 6k)

What I will try next time I am near the bike (it's at a storage place, I can't work on it during the week while at work):
- Remove plug and kick it in case there's a load of gas in the cylinder throwing things off, put a fresh plug in.
- Lean the main a lot just in case, because it seems from the jetting info 165 is on the richer side. So probably going to 155 or 150 and back up.
- Go back to the po's jetting that ran bad but idled and work up from there. I really hope I can run the JD needles though, I have them in my DRZ and they are very good in that bike.

Any input on what I may be missing is super appreciated. I haven't worked on PWK's before so appreciate any input.

[kdxdazz]

A common issue with the old carb due to a worn/corroded emulsion tube,
First get rid of that JD needle, its a terrible needle for the kdx, it allows huge amounts of fuel in at idle due to the taper and straight diameter
Try source an 1174 needle or the 1173, reinstall the airbox snorkel, drop down to a 42 pilot jet, this will improve things dramatically
I also had the same issue when I first bought the kdx, no way it would idle which made it miserable to ride in the jungle, followed all the jetting advice including RB in the US, not even close