KDX-220 jetting advice please.

[Musclegarunt]

Hi all, I've got a 2000 KDX-220. I bought it used and when I went to do the top end I found the mythical broken off piston skirt crumbled up in the bottom end!

Anyway a few months after sending my engine to Cooksey Cranks I have back a fully rebuilt engine. Pro-X rod, new bearings gaskets and seals everywhere, a Wiseco piston and new plating from Powerseal!

So now I'm tackling the jetting. When i was riding before I used the jetting recommendations from this site. 148 main, 42 pilot stock needle in the 2nd clip position.

Now I am entering unknown territory. I have replaced the jet block gasket, I am running a 6.5 slide as opposed to the 5, I have the 42 pilot jet. Air screw is at 1 turn. I have a 150 main jet and a DEK needle in the second clip position. That is a richer needle than stock but I am also running the leaner slide. Bike runs amazing. Instant throttle response, it does feel flat up top though.

It runs so good I fear I might be lean. My plug shows a brownish gray. I did have a 152 main in there but it still felt flat up top so i went back to the 150. I was running the needle in the middle clip position but it was a little blubbery down low. The bike smokes like it should not too much and not too little I think. There is a little oil coming out of the pipe but it is not drooling. I am running a 32:1 mix with Kawasaki semi synthetic racing oil.

Like I was saying it runs so good and crisp now I am concerned it might be lean. It does not bog or go BoooooooWaaahh anywhere though. It just gets up and GOES!

Any input or advice would be appreciated.

[Musclegarunt]

Okay I think I got it, have not looked at the plug though. Went out riding today, needle was too lean in clip #2, put in same needle but with .010 mm leaner straight diameter in clip position 4. I did this based on a rich feeling bottom end and a lean feeling midrange. So I have a slightly leaner straight section but a taper that comes on sooner as the taper is the same between the 2 needles, DEL and DEK, first letter is taper, second letter is length and third letter is straight diameter. Stock needle is a BGQ and it stinks... I never had it run right with the stock needle. Taper is gradual on the stocker but it starts out way leaner. It was either too rich or a little too lean but never right on.

Anyway after it feeling a little flat up top with the stock 145, 148, 150 and 152 main jets I tried a 155 and it now pulls very well up top. I settled on the stock 42 pilot jet after trying the 40, air screw is between 1 and 1.5 turns out depending on the weather which has been very cold with snow at higher altitudes. I solved my off idle blubbers with a slide cutaway change. Stock is 5 and it always has blubbered pretty bad at small throttle openings, not just 4 stroking but blubbering. Anyhow I changed to a 6.5 cutaway. Yes I have a big box of carburetor parts, slides, needles, jets the whole nine yards! I'm kind of a tinkerholic, though I hate messing with carbs but it's worth it in the end.

So stock would be
42 pilot
#5 slide
BGQ needle in #3 clip
145 main

I have
42 pilot
6.5 slide
DEL needle in #4 clip
155 main

I am quite richer than stock in the needle and main jet and a touch leaner in the slide, but it really feels spot on now. When it warms up in a few months I hope I can get by with turning the air screw out. I really hate messing with needles! Main jet can be changed without moving the carb at all though so that's no biggie.

I'm carrying and extra plug in the tool bag just in case!

[rbates9]

First off, Welcome! And good to hear you got it where you want it. Jetting is a pain.

[cornishwrecker220]

I recently tried out both CEL & DEL needles in my 220 along with a 6* slide & various jets ( i am running the 35mm kdx 200 carb ) ..the result wasnt what i had hoped for. Both needles gave a good strong noticable improvement when fully on the throttle but the low down rpm suffered as i could not get rid of the just off throttle/mid range burble dispite various jetting changes/settings etc. The 220 is ported & jetted differently than its 200 brother to give a better low down to mid range spread of power which falls flat at the higher end of the rev range unlike the 200 which pulls stronger from mid to top. Through what i tried, i belive that the CEL-DEL (although a popular 200 needle choice) doesn`t really compliment the 220s power curve as the fueling was always too rich ..in the end i settled for the 200s R1174K needle with the clip in the 3rd from top notch & a 40 pilot jet, 152 main jet & 5* slide in the 35mm carb. i found this setting works ok for me as i ride mostly tight single track, throttle response is good, jetting is clean & fuel ecconomy is excellent ..anyone with a 220 should fit the 35mm carb....it helps .

[Musclegarunt]

Did you change the jet block gasket on your carburetor? Mine was running pig rich with the stock jetting. I did all the work at the same time but I did have a little tear in the gasket. My bike runs just crisp with the jetting, it 4 strokes down low but cleans right up with a quick twist. Pretty much all 2 strokes will blubber down low due to poor scavenging at low RPM. Anything over 1/8 throttle with a load on and it clears right up.

[cornishwrecker220]

I tested all the jet blocks on 2 35mm x1 33mm carbs & found them to all be ok..i ran both CEL/DEL needles in all carbs swopping & changeing as i went ( took many many hours of testing! ) i am running the boysen rad valve which is sensitive to jetting & i even replaced the reeds & rubber boot which turned out somehow had stretched over time...i still had blubber & spooge running the CEL/DEL in my 220 when all the above was changed..after going back to the 200 R1174K needle the spooge was almost non exsistant & the blubber had all but disapeared..ok the CEL/DEL had changed the way my 220 behaved, above mid-hi end of the rev range (stronger -noticable pull ) but below this the jetting suffered making it run too rich for my single track tight trail riding..my 220 just didnt like running those needles dispite everything i tried...& i tried ALOT..i am happy that i gave it a go & also pleased that i have come to settle for the set up i am now running..theres always room for improvement just dont expect a vast amount.

[Musclegarunt]

Maybe that is the difference. The RAD valve calls for leaner jetting right?

As for too rich my bike now feels perfect. It stutters along at low load and slow speeds but cleans out instantly with an insane hit in the midrange. Also it now pulls to the moon at WFO. Not like the YZ 250 I used to have but still, apples to oranges those 2 bikes. I have a little spooge but no drooling, just a dirty bunghole so to speak

I am running the stock reeds and a UNI filter, air box hole cut way big.

Oil coming out of your pipe means your lubricating your engine good!

[crs]

So I've got a 220 SR and am looking to find either a 33 or 35 used carb to put on it...

Reading this it seems like the standard 220 carb is too rich as it comes so the cheapest upgrade is a standard 200 carb as then no messing changing needles and expensive slides - just jets and maybe clip position.

I ride steep, slower single track stuff a lot at around 1000m - and it gets v. hot and humid (N. Thailand). I really don't care about a flying top end or want a snappy powerband as can hardly use it round here - a good low / mid spread is most important.

Thoughts? Is the standard 200 or 220 carb the way to go for what I need? (People always have to lean out carbs a fair way for riding round here as some altitude, hight temps and v. humid for part of the year.)

Also, I might try to mod the standard inlet to fit the SR autolube in - anyone done this?

Cheers.

(Yes, I know about RB but that's a lot more $ and it's a PITA for me to even buy from the man - maybe a mod for next rainy season.)