Jetting Dilema - 6,000 to 9,000 ft

[ColoradoKDX220]

Jetting Dilema - Colorado Mountains 8k-10k ft

Hey all -

I'm a newb, and this is my first KDX220. After doing some searching and reading CanadienDave's articles on Jetting, I'm still in a dilemma of where my '97 KDX220 should be jetted at. I will be mostly riding in the Colorado mountains, usually between 8,000 and 10,000 ft.

Any suggestions on what I should be using for jets?

The bike is mostly stock now (except for removing the airbox snorkle), but I will be adding a FMF Gnarly G35 pipe in the near future, so perhaps I should jet it for that?

Thanks for all of the help!

 

[Wudscrasher]

Congrats on getting a great Colorado bike! I'm a new 220 owner myself. What follows below is word-for-word what a guy in my bike club suggested to me. He's ridden KDX's for over 20 years and has loads of data on these bikes, so I trust him explicitly. FYI, the only modifications on my 2000 KDX220 are an FMF Woods (35) pipe (TurbineCore2Q silencer), Wiseco piston set, TwinAir filter and the airbox snorkel removed - NOT the whole lid. In addition to what's below, invest in a 1.6 radiator cap. I rode Monday west of Ft. Collins, it was 60-65° and I was boiling over a lot. This was on rooty/extremely rocky/technical trails requiring a ton of clutch work. If your running bone stock, up the main to a 145 and pilot at 45. Also, run your coolant at 20 antifreeze/80 water. Elevation plays hell with trying to keep things cool. The 20% coolant will resist corrosion, but water has way better cooling properties than antifreeze, so use more. Good luck!

--C.J.
p.s. Where are you located in CO? I'm in Ft. Collins and belong to the Northern CO Trail Riders club - nctr.net - a great group with lots of good info.

"CJ, you're awfully close already in your setup. Good job! Here are my notes on KDX setup. Unless I mention otherwise, your setup matches mine.

Carb settings for 6 - 13K elevation, 40:1 premix
142 main
42 or 45 pilot (use 45 if you think the off throttle response is a bit flat)
Air screw approx 1.5 turns out
Needle: R1174L/2AFLQ, Kawasaki p/n 16009-1826, 2nd clip position from top (this one finishes the jetting perfectly; about $20 at your Kawasaki dealer)
Plug: BR8ES (stock), BR8EIX (optional higher buck item, but I haven't seen any practical difference)
Oil: 40:1, pump gas w/Silkolene ProComp 2+ for low smoke. BelRay H1R is easier to get and perfectly acceptable. I have samples of both if you want to stop by my house.
Gearbox oil: BEL-RAY GEAR SAVER MOTORCYCLE TRANSMISSION OIL, SAE 80W. Or else 10W40 motor oil. Put in slightly more oil than speced -- KDX's can have gearbox howl if filled to the lower side of spec. Maybe an extra 50cc of oil.
Gearing: 12/47 or 13/51. If you do more road than tight trail, 13/49 or 48 will give more top end.
Gas tank: IMS oversized gives 100+ mile range if you find the stocker isn't enough
Steering damper: Scott's
Odo: Trail Tech Endurance or Lynx. The Lynx is new -- we're running them for the first time this year.
Tires: Dunlop D756's work very well all around
Suspension settings: personal preference. We usually just set the sag and rode 'em.

-Dan"

 

[ColoradoKDX220]

AWESOME! Thanks for the reply! How your bike is set up is almost exactly where my bike will be (once I get done making the upgrades and jetting it right).

The previous owner put in a Wiseco piston, and removed the snorkle. I'm replacing the sprockets with 13T/49, and i'm running 40:1 gas.

Would you recommend a 42 or 45 Pilot? Does the 45 give you a wider range of elevations to ride in?

I'm in Boulder, however i'll be doing a lot of my riding in the Vail area as that is where a few of my friends who ride live (and where my bike currently is). I'll definitely check out nctr.net. Maybe once I get things figured out, we can go on a ride. I'm always interested in finding new peeps to ride with.

Thanks again!

 

[Wudscrasher]

I'd stay with the 42 to begin with and play with the airscrew to fine-tune it. If you were to ride lower than 6,000' more often, I'd use the 45. 45 is stock. I rode from 7,000 - 10,000 on Monday, and my plug looked very good, and didn't have any stuttering at all. If you ride around Vail, I'd say you're good w/ the 42. Also, make note of the gearing if you mostly ride technical terrain and don't need the top end very much. I am definitely switching to 13/51 for what I ride, especially after last weekend. I found that going with this setup will allow me to ride a gear higher (ie, 2nd rather than 1st), hopefully taking some strain off the engine. Take a trip up to Willow Creek Pass, Hwy 125 sometime (between Walden and Granby), and I'll show you some of the sweetest singletrack in Colorado. :nod: