New KDX rider!!

[matty86suk]

Hello folks!!
I got myself a 03 kdx220, and after riding it for a few months along with my cr250 I've decided to sell the cr250 and put some work into the kdx!!! I'll be getting the wife something when I sell the 250....

So first issue, the engine is kinda boggy at 0-1/2 throttle, I'm unsure what my current jetting is but I'll report back later. I'll post a vid riding the bike. I suspect it's running rich as I'm getting some sponge out the pipe. Bike has a power core silencer, mint factory pipe and the air box lid is removed. 500-2500' 60-80degF


Second issue, the suspension!!! It's ok at the moment considering my riding ability, but I'm getting faster by the day and I am starting to see the weakness compared to my cr250. I don't think I want to do the kx500 fork swap. I'd rather do springs and valving front and rear. Can anyone suggest a spring/valve combo for me?? I'm 205# in gear, 6'2", aggressive c rider but I'm getting faster everyday. I'm either on the throttle or on the brake. The bike is used from everything from open FSRs to Pacific Northwest tight single track, racing hare scrambles is something I'm training/practising for.

So any suggestions on the suspension upgrade will be great!!
Also, can anyone post a link to the factory service manual??

Cheers
Matty

[canamfan]

kdxoldrob has a set of conventional kdx forks with gold valves in the for sale section.

[bufftester]

Suspension is a weak point with the KDX. Stock it's unbalanced, soft up front and not so soft out back. RaceTech has a good spring rate calculator on their site. At 205 the bike is undersprung for aggressive riding. You can either go the gold valve route, or play with the shim stacks yourself, plenty of threads on here about both those subjects. Also, stock the bike is pig rich, a run through the jetting guide will square that away. While you have the carb off to record jet #s give it a good cleaning. Oh, and welcome to the site!

BTW there is no link to a FSM here as it's not public domain and the site wants to avoid any legal issues. There is a link on the home page for the Cyclepedia version, or you can ebay a version.

[6 Riders]

Matty, I had my forks done at LTR in Port Orchard. Les did a great job making my stock forks work wonders for my riding around here (PNWet). I've never had to touch them since. He also does rear shocks if you like. This time of year is a great time to hit him up, since it's a little slower after the race season.
I told him my weight (actual not "what I wish I was) and the type of riding I do...from Dessert 100 to Tahuya whoops at a good click to super tight single track. He is a genius at suspension tuning!
I paid $250 (cash) for full rebuild, a "balancing hole" drilled into the damping rod and new springs for my weight (which he actually had sitting in his attic). I did supply the seals and did not need bushings.
I can jump that bike now...not that I want to, but IF I catch air, it handles the landings very nicely!

[matty86suk]

Matty, I had my forks done at LTR in Port Orchard. Les did a great job making my stock forks work wonders for my riding around here (PNWet). I've never had to touch them since. He also does rear shocks if you like. This time of year is a great time to hit him up, since it's a little slower after the race season.
I told him my weight (actual not "what I wish I was) and the type of riding I do...from Dessert 100 to Tahuya whoops at a good click to super tight single track. He is a genius at suspension tuning!
I paid $250 (cash) for full rebuild, a "balancing hole" drilled into the damping rod and new springs for my weight (which he actually had sitting in his attic). I did supply the seals and did not need bushings.
I can jump that bike now...not that I want to, but IF I catch air, it handles the landings very nicely!

Sounds like a fair price for springs and valve work, I'll look them up. How does it ride now?? Can you describe the difference versus stock?? I'm wondering if it is worth going with GOLD valving front and rear with springs or just reworked valving with springs....???

Also, I pulled the carb out today and gave it a good cleaning. Simple carb that's for sure, I like the choke valve how it is a rubber seat versus the needle seat on the pj28 keihens.

My jetting is factory; 42 pilot 155 main, 2nd clip needle, I assume stock slide and needle. After the carb clean it started first kick with no choke, I warmed it up and set the idle above normal speed to tune the AF screw. I'm at about 3.25 turns out on the AF screw, I'm thinking I need to try a 40 pilot and maybe move the needle down a notch or try a 152/150 main..but then again fall and winter are around the corner and I bet she'll lean out in 35-55defF temps we normally get. I'm gonna order some jets and a rebuild kit...what jet or jet kit do you guys recommend? I'll get her running perfect, we'll figure this out....

[bufftester]

Do yourself a favor and run through the jetting guide verbatim without skipping any steps...trust me, you will save yourself hours of wasted fiddling.

[matty86suk]

Do yourself a favor and run through the jetting guide verbatim without skipping any steps...trust me, you will save yourself hours of wasted fiddling.

Yes, that's what I was doing, I'm at 3.25 turns out, anything above 2.5 turns indicates a rich pilot, and bubbley to 1/2 tells us to lower the needle. Is there a kit that gives me everything I need to jet the carb?? Are aftermarket needles and or slides worth it??

Cheers

[6 Riders]

Sounds like a fair price for springs and valve work, I'll look them up. How does it ride now?? Can you describe the difference versus stock?? I'm wondering if it is worth going with GOLD valving front and rear with springs or just reworked valving with springs....???

My forks are 94 USDs, (same fork as the 95+ but USD) no valve work can be done, they can be tuned, but they are not valved. For what gold valves, springs and new hardware + Labor, you are better off doing a fork swap and having the valve work done on those...In the long run, it's cheaper for better performance.
My forks handle excellent. I might struggle a little in low speed stuff, but compared to stock, it's coasting down a sidewalk. The stock springs where .29s, the 95+ springs are .36 (I think). I ended up with .41s (for a 160# rider + gear). I have them on my 95 KDX until I source a fork swap (and have cash).
I figure, after buying a front end off of another bike; $170 for clean and revalve and about $50 for lowering (stock KDX forks are short), if it needs springs and hardware add another $150 for both.

To have KDX forks set up w/gold valves....you are looking at $170 for valves, $150 for springs and hardware around $100 (guessing here) for labor. AND you still end up with pretty inferior forks (from a tuning perspective).
So pick your evil...
Here is a link to LT (call him he will answer your questions): http://www.lt-racing.com/

[bufftester]

That's why you want to record your jet sizes before you start, sounds like you need to go down on the pilot a size or 2. There are other needles and slides, but I have always gotten great performance with the stock needle/slide once the carb is jetted properly. Of course I don't live in the Himalayas and do most of my riding between sea level and 5k feet.

[matty86suk]

I think the first order of business is to do the top end, this bike is low hours and I'm pretty sure the piston is OEM. I'll also repack the silencer and service the KIPS. Worn piston and rings will mimic a rich condition I've read and the jetting guide says I need to start with a fresh top end and exhaust.

Anyone have a link/source for a complete top end kit?? I guess weisco is the way to go...

As for the front end...it's obvious the kx500 is the superior fork swap/upgrade for the kdx, I guess I have to consider it comparing the cost of upgrading the stock forks versus a conversion...

What year is the best, most straight forward swap?? I've read the kx500 forks and triples do not require and machining, bolt on...? What year kx500 front should I look for?? Beer the better I assume???
I'll look for the complete front end, forks, clamps, stem/bearings, wheel/axle/rotor....I've also read the kdx caliper will bolt on???

Any input would be great!!
Cheers folks