02 200 final jetting and carb adjustment report

[Actionman]

Got a package of new carb parts today: new bowl oring, new drain o-ring, jet block o-ring, 152 main, new needle clip, new floats, and o-ring and washer for the air screw(not used on these carbs so I bought one for a pwk38). My ownership of this 02 started with a rich, blubbery bike that poured oil and smoked up the trails as well as running like crap until full throttle. After a few months of jet juggling and ratio changes, I have finally got this thing running like a strong 2-stroke should run! Main-152, pilot-40, clip 2nd from top, airscrew @ 1 3/4 from seated and airbox lid/snorkel on the airbox. I could go down a size on the pilot and up a clip on the needle probably, but I am erring to caution and leaving it a tad rich since winter is coming. The o-ring on the airscrew is a very worthwhile addition I feel since I swear I noticed a little crisper throttle response with it installed.
I made a new idle screw out of a bolt and that was a big help since the plastic one didn't have any head on it! The jet block o-ring was stretched out due to boiling the carb when I cleaned it and the new one really seemed to tighten up my low end response as well. Finally, the new floats were set correctly from jets r us, and my old bike now wheelies in just about every gear. The previous owner rode it today and couldn't believe how strong it ran! That 152 main gave it a smooth top end and it sounds healthy as an mx bike when I wind it out. I am finally, finally finished and happy with my bike! A big thanks to all and everyone who helped me on my long quest to getting it right! I am fully convinced that the Kdx of this model is the perfect two stroke bike. It is just that good! Torque of a 250, overrev of a 125(but the weight of a 500 unfortunately)! :)

[Actionman]

Well, one good day of running now its back to running like crap lol. Rich, throaty sounding exhaust with a lot of smoke and a gas smell. I found out my petcock is always feeding gas even turned off, but it seems like it would clean out instead of running worse as it get warm, but it doesn't. I will step back down to the 38 pilot and make sure nothing is clogging the main, and if that doesn't help I'm selling this thing and riding my rm 125 instead. Crank seals aren't leaking, by the way. No loss of coolant and not a drop of oil used either. Plug is clean but wet with gas. It seems like anything above a 38 pilot and my bike will not run correctly. Ill find out tomorrow whether its the jets or whether I'm selling it. For what little riding I do that rm will be fine if I do sell. I'm hoping its the pilot though.

[mcpga]

What elevation?

[Actionman]

+400-700 ft above. I've been thinking about it and I think the pilot is too rich. I was running a 38 with clip in the top groove and a 155 main. It ran great except it had a very very slight blubbery spot that I attributed to my needle being a touch too rich. Yesterday I rebuilt my carb and dropped the main to a 152 and lowered my needle a notch thinking that the leaner main would compensate, plus I raised the pilot to a 40. I'm going back to the 38 and leaving the new 152 main in then ill raise the clip again if needed. I may at least remove the snorkel first Nd see if It gets me close, but I want the lid for noise purposes. I get mad and threaten to sell my Kdx but ill never do it lol. I just changed jets that didn't need changed. I think the 10 degrees warmer weather yesterday might've been the difference in how good it ran. BTW: I NEVER have to use my choke to start my bike, regardless of pilot size; is that normal? Never seen a bike that didn't need choked when the engine is stone cold.

[mcpga]

I'm no expert so I wouldn't be able to offer any advice on your choke issue. But that does not sound right. I do know that 2-strokes like air. I would open up that air box. Thats the first thing I did when I was trying to lean up my '03 200. I also leaned up the mix to 40:1 and of course leaned up the jetting to 155/42. I'm at 1000' ASL. Mine still smokes and spooges a little but not too bad and it runs great and I never foul plugs...

[Actionman]

Yeah. I may be too married to the idea of that airbox lid and causing myself grief. I don't see too many folks with h model 200's using a 38 pilot so I'm skittish about going down that far. I think though that most folks ditch the lid when jetting. Most users seem to average a 40-42 but my bike WILL not run right with either. Never really tried to jet it without the lid/ snorkel to be honest lol. Going to ditch the snorkel at least and may end up adding a few holes with foam filters by the time I'm done.

[Roadhazardguy]

You're not going to seize the engine on too small of a pilot, it that's what works use it.

[mcpga]

Have you checked to make absolutely sure that your choke mechanism is functioning 100% properly. Seating all the way down when it's off. I'm not sure what could go wrong with the choke, but I used to ride 4-strokes and it was pretty common for the hot start plungers not to seat all the way which would make the bike run like crap no matter how you set it up. I know the choke is not a cable actuated, spring loaded device like a hot start plunger but if the choke is not functioning properly, it would either make the bike hard to start or cause an overly rich condition. Just a thought...

[Actionman]

Well, I have a very strange update. I forgot that I had removed the o-ring and washer from the air screw I had installed the day before. Now remember that a stock pwk doesn't even have those on the screw. Anyway, I went out this morning, REinstalled the o-ring and washer, and it started running almost as well as it ran Monday. This leads me to believe that a fair amount of slop must exist in the shaft of my airscrew, or the screw itself is worn somehow. The bike could use a drop if the needle clip no doubt, but WITH the airscrew o-ring I can run a 40 pilot. Without, a 40 is too rich. I am absolutely stumped at what's going on with this thing! Another possibility is I might've had some water drops in my gas, because I had cleaned the tank out Monday; BUT it seems like I would've had problems then and not the next day. Oh well, I'm not a choosy beggar, so whatever it was it now runs fine again, lol. Back to being happy. :)

[royadams]

Did you replace the float needle as well. It sounds to me me like the needle is sticking some times. Do you run a fuel filter, it may be getting trash stuck in it.

[Actionman]

Well, I am going to look like an idiot but here goes: I disassembled the carb again, and found a clogged pilot. I had hooked my fuel line up and ran it before I remembered and reinstalled my inline filter. Bike ran mucho better, but still had a rich spot. Raised needle clip, bike ran better but still a rich spot. Put in 38 pilot, bike ran even better but a slight rich spot when rolling on throttle. Looked through my box of carb parts to take inventory.... And found a new jet block gasket. "Hmmmm.." I thought, "I only ordered ONE of these gaskets...." I had forgotten to change out that damned jet block gasket! Took out the screws and the old gasket was distorted and shot to hell. I had taken the block apart but put it back together without installing my new gasket, lol. My only defense is that I'm taking a giant dose of oxycodone due to another bulging disc, and I seem to um, "forget" things lol. Anyway, THAT was ultimately my main jetting problem. The clogged pilot was all that was wrong with it today. That new jet block gasket really solved my ills! It's all back together now and runs great. I think that's why I didn't need my choke as well, but ill know for sure tomorrow when I cold start it. Holy cow this has been a long and drawn out process. Anyone new to the Kdx: replace that damned jet block gasket if you buy a used Kdx! THEN you can get it jetted correctly, lol.

[Actionman]

Yep, it's totally fixed now! I replaced the jet block gasket yesterday and went for a long ride today; it runs like a different motorcycle. Revs sharp as a knife, doesn't smoke, and actually had to use the choke to get it started from dead cold. I actually had to raise my jetting to a 42 pilot, 155 main, and needle in top clip . Remember that a 38 pilot was what it did need to even be close to running right before I replaced the jet block gasket. I can slow to a crawl in fourth, smoothly twist the throttle, and it pulls cleanly through the whole range without a hiccup, hitch, or stumbling. The front end will come off the ground in 4th and 5th if I get too frisky with the gas as well. I'm looking forward to my next all-day ride now since it runs so well. Finally got it! Again: to any new Kdx owner who can't get rid of burbling jetting- REPlACE THE JET BLOCK GASKET!! Jets r us has them for $4, so buy a couple so you'll have spares when you need them. It's the very first thing I should've done when I went that low on my pilot and still couldn't get it running right. That should have been a red flag that something was amiss.

[Actionman]

Another oddity for the list: the bike runs better with a br9es instead of the stock br8es. Had 2 of each new plugs and put the 9 in today and it revved out and accelerated cleaner with the colder plug. Each plug gapped to spec and tried both of each type. Plug chops on the br9 showed a pretty tan plug, whereas the br8 was a little on the darker side, which is the opposite of what I would have expected. Chalk it up to the strangeness of my Kdx experience lol.

[Malarkey01]

Great thread Actionman.

I'm very new to bikes/KDX. Just bought my 96 KDX the other day and am having same problems. Lots of blurbing..etc etc esp at higher RPM.

I'm going to take the carb apart and do some cleaning. So you made ALOT of adjustments everyday. Being new to this, my question is, everytime you made a carb adjustment and/or put in a new jet or changed the needle, you have to take the whole carb out and reinstall each time just for those simple changes correct? Yikes...:(

And it sounds like I should figure out what the "jet block gasket" is and get one of those on order!?

Thanks!

[Actionman]

I actually made TOO MANY changes at first. Heres what Id do if I had it to do over:
1.make sure your petcock filters are intact and clean.(mine weren't there, and I kept getting crud in my pilot jet).
2. clean out the carb and jets with warm soapy water.WARM, not boiling hot, or youll ruin that stupid jetblock gasket!)
3. Clean and oil the air filter properly.
4. SET THE FLOATS!!
5. Start out with a 42 pilot and 155 main with needle in the middle clip and adjust the airscrew as needed if you have an H model 200. these
jets are right in the middle of the sizes that most h model users seem to use. It might save you from buying sizes you wont need.
6. Buy a jet block gasket from http://www.jetsrus.com . Its $4, so buy 3 or 4 with your jets. Here is the link to the oring-
http://www.jetsrus.com/individual_parts/021_532_su.html
7. I live in Southeastern Ky at an elevation of 300-500 ft above sea level, and Im currently running a 40 pilot, 155 main, needle in top
clip, airscrew at 1 1/2 out, and airbox lid and snorkel installed. It still has a slight richness at the very bottom, so I probably need a 38 pilot,
152 main, or remove my lid and snorkel to make it work with the 40 and 155. I dont like the extra noise, so I am loathe to remove the lid.
8. Forgot to add that you need to repack your silencer and make sure the kips is working or your jetting quest will be filled with heartache and
gnashing of teeth. I also run at 32:1 fuel/oil mix.
9. Ive found even still that theres a very, very slight rich spot right above my half-throttle setting, which I can feel by putting the bike in 3rd
gear from a crawling speed, then smoothly accelerating through the throttle range. My clip is in the top, so I may need a step leaner needle.
Some may not mind that slight spot, but I will eventually buy another needle because I demand perfection, dammit. lol.
I cant think of anything else, so good luck and follow the above steps to avoid the giant headache I endured from making too many changes
and not sticking to the basics.

[Actionman]

Great thread Actionman.

I'm very new to bikes/KDX. Just bought my 96 KDX the other day and am having same problems. Lots of blurbing..etc etc esp at higher RPM.

I'm going to take the carb apart and do some cleaning. So you made ALOT of adjustments everyday. Being new to this, my question is, everytime you made a carb adjustment and/or put in a new jet or changed the needle, you have to take the whole carb out and reinstall each time just for those simple changes correct? Yikes...:(

And it sounds like I should figure out what the "jet block gasket" is and get one of those on order!?

Thanks!

Yep, you have to remove the carb each time. I simplified it by leaving my gastank bolts out and removing the tank each time for more room. Sounds like a lot of hassle, but I actually frayed and broke a throttle cable from removing it from the top of the carb with the carb angled to the side like most people would do. I finally went to a local abandoned strip mine, removed my radiator shrouds and takn/seat bolts, taking all my tools and jets with me, and spending about 6 hours just replacing jets and testing throttle settings. Since there wasn't any neighbors around, I could rev the heck out of it without the cops nabbing me. Leave the seat bolts in so that it doesn't fly off causing you to sue me due to injuries you might sustain, lol. Itll take a LOT of time to get it right, but if you follow my list above youll save a lot of misery. I spent DAYS cleaning out my carb after every ride because I didn't know my petcock filters were missing! I have a 02 200, so Im not sure my jet numbers are applicable to your 96, so someone might jump in to help you with that.

[Malarkey01]

Thanks!

I need to figure out what the petcock filters are and the Jet block gasket and order some jets.

I've done some research on what jets I want to/should run for it. Right now I am at 100ft so will just try to clean what is in there right now and see how it runs. I will order some new jets as the bike will mostly be at my cabin which is about 3,000 ft elevation. From some jetting threads on the interweb, sounds like it should be around 42, 152 or 40, 150. So i'll probably order those and go from there.

THanks for your help!

[Malarkey01]

Actionman, see the link in this post to the sound/video clip. Is this what yours sounded like pre-carb cleaning/jetting?

[Malarkey01]

In addition...I've never needed to use the choke. The bike starts first kick hot or stone cold without the choke...

[Actionman]

Actionman, see the link in this post to the sound/video clip. Is this what yours sounded like pre-carb cleaning/jetting?

I didn't see a link. Mine had a choppy sound when revving it out, and you could smell raw unburned gas plus there was oil pouring out of my exhaust. If I was riding at full or near full throttle, I could back of the throttle a tad and the engine would start loading up and burbling and pouring smoke. Btw: the petcock filters are inside the gas tank attached to the fuel petcock. If u remove it from the tank check them for tears and clean them with a spray of carb cleaner if they're in good shape. When you put the petcock back into the gas tank, don't over tighten the bolts that screw into the tank or you'll strip out the pressed in threads on the tank, then that's you, screwed. Just snug em up!