Hi everyone. I have some questions.

[HareNHound]

Hello,

My name is John and I ride harescrambles in the midwest area. I have been working on a project bike for a friend. He purchased a 1999 KDX 220 from a local rider. When we rode the bike we noticed that it was way off as far a jetting. "On pipe" was a long way and a lot of work away. The bike had a lot of nickel and dime problems, however it was for sale for the right price.

I started by disasembling the top end. I disassembled and cleaned throughly the kips power valve unit. The kawasaki unit is remarkably complex in it's operation. So put the power valve back together and dropped the cylinder back on the bike. I put a new piston, wrist pin, and compression rings in the bike. This way at least I know it is not mecanical.

So on to jetting. My friend purchased a new FMF rev pipe mated to a pro circuit canister.

The jetting I started with #150 Main #48 pilot. Needle Jet Position #6 from the bottom. Way too rich. Air Screw out way too far.

Changed to #145 main on clip 3 from bottom 48 pilot air screw out way too far. Better still way too rich up top

Droped needle to position #6 in the #145 main jet. Ok getting close here. Is hitting pipe now, however if you put around for a while you have to wait a few seconds for it to come on pipe. If you ride it around on pipe runs great.

Only question here, the bike does this wierd thing on decel where it kind of wants to go ping......ping.....ping...... Is this because it is getting too much fuel through the pilot?


Jetting recomendations on Just KDX web site say#150 main jet.

Just would like opinions.

 

[mcoker]

Sounds to me like you could probably go leaner, try moving the needle up one more notch (to the 2nd from the top position)

Also, click here if you haven't already

 

[davidg]

You said it's 220, does it have a stock carb on it? The stock jets are 145 main and a 42 pilot. You might need to go a little smaller on the pilot, that is if it's a stock (33mm) carb.

 

[canyncarvr]

re: 'Jetting recomendations on Just KDX web site say#150 main jet'

Where does it say that?

As davidg says, a 42 pilot and a 142/45 main is in the ballpark for the 'H' 220. That's what I read on the justkdx site anyway.

Needle position #6 from the bottom? FFR, that's clip position#1, however many positions there are! ;)

No-one can tell you how to jet a bike. It's too much a variable process..based not only on different mechanical issues, but rider styles and conditions. You have to set the main first. That can only be done (excepting a bunch of $$ and equipment) with the use of a new plug and a WOT plug-chop test with subsequent plug examination with attention paid to the mixture ring at the base of the insulator.

Yes, I understand that a good tuner can 'feel' the jetting state and can tell you exactly what's up.


A 48 pilot is NOT it. Neither is a 150 likely to be 'it' either.

Open up the airbox lid.

Repack the S/A.

Start with CDave's recommendations on his site. What you list is not what he says.

Run appropriate tests and adjust from there.


Do some searching on this site...pick up some 'C' series needles. Probably J, K and L diameters. Probably an 'L' for the #5 TV (if that's what you have) The plug load up when you 'ride it around for awhile' will be gone.

Might as well do the 'new bike prep' on CDave's site, too. Chances are excellent the suspension linkage is hosed. It has to be serviced several times a year to 'live' very long.

Your friend owes you a few cases of beer, doesn't he? Heck.....maybe beer for life!!

;)

Have fun!

 

[HareNHound]

CanyonCarver,

I will go and buy those needles. Does the taper increase or decrease as the letters go?

I repacked the silencer when I started the project.

I will be removing the airbox lid today, may be looking for some air.

I have looked at jetting rec's on dave's site. I am not sure, it may be a 200 carb on that bike.

I will find out and re-post.


A BIG Thank You to all who replied. You guys are awesome.

Thanks

John

 

[canyncarvr]

Check out CDave's site for his 'needle decoder' section.

The taper increases as the letters go up:

• A=1'00" (they list them in minutes/seconds for some reason) or 1º
• B=1'15" or 1.25º
• C=1'34" or 1.5º
• D=1'45" or 1.75º
• etc.

It's important to keep in mind that as the angle increases, the point at which the taper start drops on the needle....your straight diameter stays straight longer (for the same L1 needle).

That's because the diameter used to determine L1 is 2.515mm (the 'magic' number), not the place on the needle the taper starts!

Capiche?

Get that relationship, and a whole lot of needle FM becomes clear!

BTW..thanks for working on your buddy's bike. You must be a good buddy.

......you didn't BUY the thing for him, too, did you? That might be a bit kinky or something.

NOT THAT THERE'S ANYTHING WRONG WITH THAT!

;)

 

[HareNHound]

When I removed the airbox lid, boy what a difference. Thank You!!!

Now with newfound power (however not carburated perfectly) the clutch has decided that it cannot deal. The fibers are fibered out. I cannot wait to see how notched that basket is.

Any tips before I get started??

By the way Canyon Carver,

My buddy did buy the motorcycle and all the cool stuff that went on it. (IMS Tank, Rev Pipe, FRP gaurds.) But you see, the bike stays at my house. Which means...... when it is spot on perfect I will go back to the days when I owned a KDX. I LOVE KDX's. Nothing handles like a KDX. And when you can get the motor perfect and kinda fast they are so much fun. So you see I have alterior motives.

I think with that lid removed we are real close on the main. It's coming on pipe every time now. It's just not coming on real hard, like I would expect it to. The bigger problem is when the air screw is a .75 turns out it does not want to idle with that pilot jet. I'll get the clutch fixed first and go from there on jetting.

 

[canyncarvr]

You might consider xr250r plates for the kdx. They have considerably more friction area than the kdx oem plates. FRP sells vesrah plates made for the xr that he repackages in kdx quantity.

FYI, you cannot use the kdx outside conical spring & seat with the wider plates.

Most riders like 'em alot. I haven't quite decided on 'em yet. Still, they're an option.

Note the two same-sized washers in the basket assy. One under the basket, one under the clutch pack. The 'bottom' one likes to get lost by sticking to the basket on removal.....and falling off when you aren't looking.

A recent thread shows the necessity of proper torque on the basket nut on reassy. It's here.

You prolly know all that...but you did ask! ;)

 

[Canadian Dave]

It sounds like you're working your way through some typical problems with a used bike, fun eh?

A few things to add. If the stock piston wasn't replaced with a Wiseco piston I'd consider doing so. I wouldn't re-ring a stock 220 piston. The stock 200 piston is of excellent quality but the stock 220 piston can crack if the engine is worked hard, modified etc. General rule of thumb is to replace the stock 220 piston when you rebuild the top end. Not all pistons are bad but there are some and you don't want it to be yours.

If you followed the factory shop manual to the letter when you reassembled the top end be aware that some manuals wrongly identify the left and right sub port valves resulting in incorrect timing. For more details see the Justkdx web site. Check out the article on removing the top end as well paying particular attention to the discussion on properly supporting the main kips shaft when removing the nut on top.

You'll need to measure the carb and determine if it’s a 33 or 35mm carb before jetting. From your results I'd say it’s a good bet it’s a 33 though.

 

[HareNHound]

I have you to thank. If it were not for your site I would never have gotten that power valve installed correctly. Yes the manual I was using did not properly identify the valves. I even got the dremmel out so I could see how the actuator for the power valve worked. As soon as you reved the dremmel past 7000, whak that thing snapped open. I thought it was a really cool design.
The person who last did a top end job on this machine put the power valve together incorrectly. The KIPS section cleared things up for me. Thank You.

After I get this clutch done I want to find out if I can make this KDX come on real strong. I want it to snap hard. I was planning on riding it like a 125. Do guys do that much on 220's.

See I am a heavy guy. I am 6'6" and 260 pounds. The problem with the KDX is that right now it's not enough motor for my level and the forks can't take really aggressive riding.

 

[canyncarvr]

So some searches on this site for general information that will help you get what's available out of the 220.

Whether that is what you're after remains to be seen.

Don't make the mistake of trying to make a silk purse out of a sow's ear (literally translated). The 220 is a mild configured engine regarding port timing and carburetion. It's not going to be a 125.....ever!. It can be made to run better than it does in stock trim, but it's not going to be a 125.

Yes, I understand you said ride it like.., as opposed to turn it into one. Still.......

Don't know how your bike is configured...and that's a starting point. You can't figure out too well what you need to do if you don't know what you've got in the first place.

...which takes us back to the beginning. I still don't know where 'recomendations on Just KDX web site say#150 main jet' came from. That's not what I read.

And what carb DO you have?

Realistically, there is one way to get a 220 to:
1. Take aggressive riding
2. 'Hit hard' with a close to 300# (with gear) payload
3. Ride like a 125

Get another bike. Maybe a 520 pumpkin or something.......

Read thru CDave's tech tips and hop-up guide to get on track with what the 220 needs. He covers reed systems, carb tweaking (like a 36mm bore with the RB mod) and of course jetting.

The kdx frontend is a known weak spot. At your weight, the shock isn't up to snuff, either.

I think you're barking up the wrong tree.......

 

[HareNHound]

Canyon Carver,

I was going on the assumption that this bike had a 200 carb on it becuase there was a lot of documentation about this mod in a 3 ring binder that came with the bike. The guy claimed he put one on the bike. He did not... I have investigated further and found that it is the stock 220 carb.

So back when I was looking a jetting specs I was assuming that I was jetting for a 200. Because it says on the CD site that when using 200 carb on 220 do as the romans do. Use 200 jetting for 220.

" 1995 to 2003 KDX200

Stock -Run the stock R1174K jet needle in the second from the top clip position, 45 pilot jet, 155 main jet and fine-tune the pilot circuit using the air screw."



That explains that. And the 145 main on a stock 220 carb should be right on and it is.

Please don't think that I am being too critical of the KD. I am just trying to learn how to shine a quarter. I am tring to make a silk purse out of a sow's ear because many others have been able to make the KDX a serious motorcycle. I have much to learn about tuning, but I am learning a lot every day thanks to you guys.