89 KDX why so different from 90-94?

[John Cena]

Hi I just got a 89 kdx a while ago and took apart the carb this morning and found it has the stock 48 pilot, 158 main, #6 slide and r1172N needle. I've just checked and the 90-94 seem have have way leaner jetting stock is the 89 engine really that different? I was also hoping someone could give me some advice on what might be a close starting point for jetting this bike. I'm broke so can't afford lots of different mains and pilots etc so if anyone could give me something that would be close to proper jetting that be great.

here's my bike specs: Riding at around 300 feet above sea level, temps around 68F or 20 celcius

89 kdx 200
air box lid removed
FMF fatty pipe
FMF power core silencer
Boyesen power reeds
I run 92 octane fuel.
and amsoil injector oil at 32-1

Thanks for any and all helps! Nice site guys!

[Indawoods]

John... I think we need to know how it's acting. Is it lacking power, bogging, fouling plugs? Why do you think it is off is what I guess I'm try to ask. Sounds a little rich to me but it may not be for your bike because the removed air lid will lean it a fuzz.....

[Indawoods]

My brothers 89 is very similar to yours in mods and he is running a 155 main, 48 pilot... and his runs....well, perfect.

[John Cena]

It seems to lack power to do some wheel lifting with out reving and poping the clutch unless i'm moving then I can get the wheel up in 2nd gear with 13/50 combo sprockets. Also at temps around 14F or -10C When I put my hand behind my silencer and give it some throttle I get a nice wet oil pattern on my palm. I've repacked my silencer too. Heres a picture going up a hill at about 41F or 5C. Is your brother running the stock needle?
http://home.cogeco.ca/~lleepp/Oakville% ... 030113.JPG

Also im running a NGK iradium 8 heat range plug

I fouled 1 iradium 9 Heat range plug in about 14F or -10C

Thanks for the help indawoods

[m0rie]

There 89-94 engines are identical, the 90-94 jetting is actually closer to being correct in most cases than the 89 stock jetting. For reference here on the coast @ 0-1500ft i'm running a 150 main, 40 pilot and CGK-3. The CGK needle does require a different jet set than the R1172N needle but you should be able to lean out the pilot and main at least 1 or 2 sizes. $35 in brass (jets and needles) from sudco will go a long way towards giving you a lot of options for making that 89 scream.

-Maurice

[John Cena]

Thanks Morie! Is the R1172N needle richer then R1173N? Also how does that translate to the CEK or CGK etcs coding?

[KDXGarage]

Welcome to the site, John Cena. I didn't see your usual gold chain in the photo.

I have a 1994 KDX200, so maybe I can offer some suggestions. With the same jets, it will definitely run differently at 14 degrees than 68 degrees. The colder it is, the larger the jets need to be. The warmer it is, the smaller the jets need to be. If you have it jetted perfect in the dead of summer and do not change the jets before riding in 14 degree weather, you may be in danger of running lean and causing engine damage.

What postion are you running the needle clip? There are five grooves in the needle, with the one at the top being #1, and the bottom groove being #5. I think stock is position #4.

Upon Jeff Fredette's suggestion, I went from the stock R1172N needle to an R1173N. That leaned it out in the 1/8 - 1/4 throttle range. If you look at Keihin part numbers instead of Kawasaki OEM part numbers, I went from the stock BGN to a BGP. If you have never been jet shopping, buy it based on the Keihin part number instead of Kawasaki OEM part number when possible. It is a good bit cheaper.

Any chance your rings, piston or reeds may be wore? Not wore out completely, but just not real fresh? Also, how clean is your air filter? Do you know how clean your KIPS valves are?

For 68 degrees, I would suggest coming down to a 45 on the pilot and seeing how that works for you. You may want to try a 155 main. Also, try to go up at least one clip position on the needle. Try these one at a time, so you know the affect of each.

I just trail ride usually, so I am not always revving it high. For me, a 9 heat range plug is just too cold. I had a lot better success with an 8 heat range plug.

By the way, my bike's mods are:
airbox cut away to only leave enough room to mount regulator
Twin Air air filter
stock reeds
FMF pipe
FMF spark arrestor
92 or 93 octane gas
Kawasaki 2-stroke oil at 32:1

Jetting is a very personal thing. What works for one, may not work for another. You will just have to try each change and see how your bike runs. It can seem like a slow process, but it is worth it in the end.

... and get some boots! I used to be too broke to afford boots, but once I got some, I felt a lot more safe and less worried to go fast. Even work boots would be better than running shoes / tennis shoes.

[fuzzy]

Only one way to know for sure. Do a WOT plug chop, and jet your high, and low from there....Jetting recomendations are pretty much worth a grain of salt. Fredett's worked well for Inda, and I before we learned how do do it properly but we're from the same state/elev...

Do I dare do this again Maybe we should 'rip' this ?

http://justkdx.dirtrider.net/carbtuning.html

[kdxquebec]

i have a 89 also and i dont understand why they change jetting in 90.mabe they realized it was too rich.
i run 160 main jet with 48 pilot neddle 2 clip from top. fatty pipe +boyesen power reeds ang br9 plug 40:1..i know i my jetting is rich but no spooge and bike run great bottom to top.fouled a plug once in 4 years. thanks for the jetting patern i read here.i think i will play with the brass next spring to be more close to perfection.

here is a plug shop i did with this jetting setup! (with a new plug and good procedure)may be it can help you.

http://groups.msn.com/KDXRidersCommunit ... otoID=1037

[John Cena]

Well after reading all this great info! I think I should be fine with the R1173N, 45 Pilot , i'm gonna keep the 158 main just to be safe. Cause I' like to get wide open at times

I'll try the leaner needle first.

Sry about forgeting to mention I've been using this winter.

R1172N needle in 3rd from top spot. and 48 pilot 2.5 turns out.

Thanks for all the help guys

[John Cena]

Well I went down to a 45 pilot with air screw 1.5 turns out. when I give my bike throttle it feels like its gonna take off from under me only cost me 8 dollars canadian for the pilot from my dealer It definatly has more snap to it down low. And I geared down from a 50 rear sprocket to a 49 so wow Next change is my needle.

[KDXGarage]

Hey, all right! I am glad to hear that you made a change, and it suits you. If you buy a needle from the dealer, it is usually high. You may want to try a mail order company when you get around to fooling with the needle.

Good luck!

[John Cena]

Hi kdxquebec! I was just wondering if your bike smokes at 3/4 to wide open? Now that I installed the power reeds with a 158 main my bike smokes near wot. So i'm putting in a 155 main tonight. I guess im alittle higher in elevation then you? was that plug chop at wide open? and for how long?

Thanks!

[kdxquebec]

The bike do not produce a lot of smoke at 3/4 to wide open.Do not forget those power reeds make the bike run richer.

Here I think we ride about 100-200 feet above the see level,and the temps are cooler .run the bike at 45F-70F

Here how I did my plug chop. the bike was warm and I putted a new plug in.Then on a fire road I rode the bike in 6th gear wot for 15-20 seconds.Then stopped the bike with the kill switch.removed the plug and replaced with the old one.