"detuning" KDX220 [Archive] - Kiwi Biker forums

FROSTY

30th January 2008, 11:05

My KDX is on the whole a bloody nice bike. Its light easy to work on etc etc.
The only problem with it is its got a performance pipe on it. Its rather er Peaky in power delivery.
Ive been offered a factory pipe to fit to it but before I do so.
As a rule do I need to rejet and reset reeds as part of this exercise?
Any feedback would be apreciated.
PS--Still looking for a tank

ArcherWC

30th January 2008, 11:36

possibly will have to look at rejetting, you wont have to do anything to the reeds

scott411

30th January 2008, 11:43

do not need to rejet going back to std pipe, did you try baileys for that tank?

ArcherWC

30th January 2008, 11:57

Or you could just HTFU frosty and stop riding like a girl

FROSTY

30th January 2008, 12:28

archer--not a matter of hardening up dude.As is it aint suitable for the short tight track Im riding it on. Im either fouling the plug or slipping the clutch -On a fast open track it flies

cheese

30th January 2008, 14:15

Maybe gear it down a bit?

humai

30th January 2008, 14:23

Your KDX shouldn't be fouling plugs, no matter what trails you ride. Your current jetting must be hugely rich if it's fouling plugs.

If you put the original pipe back on (the double skinned heavy grey coloured thing), you'll shave all the good stuff off the power curve without necessarily putting anything back into the curve down low. I have converted pipes the other way and saw no disadvantages but a heap more peak power in so doing.

KDX 220s were quite rich in the lower mid with factory jetting. Their 33mm carbs used a #5 slide (the 35mm carb on the 200s had the leaner #6 from memory), which, in conjunction with the supplied needle, even when the needle was on its leanest groove, meant the mixture was very rich just off idle (where you might be in amongst the trees on a tight single track). Mine was very rich as delivered but still didn't foul plugs or spooge much. A 35mm replacement carb with a #6 slide cured the issue for me. The main was a 155 but I can't remember the needle, sorry (the bike was sold years ago).

You may be able to find another leaner needle profile and keep using the quite-expensive-to-replace #5 slide. YMMV

Good luck

chris

30th January 2008, 14:43

slipping the clutch
You should be doing that, Tony. Keep the revs up and slip the clutch to control your progress.

Taz

30th January 2008, 16:02

Good KDX site here too.
http://www.kdxrider.net/forums/

B0000M

30th January 2008, 16:10

every aftemaket pipe ive ridden with has increased low end power probably more so than increasing top end power. putting the standard pipe of id imagine will make it even harder to ride

GR81

30th January 2008, 16:14

flywheel weight?

NordieBoy

31st January 2008, 07:27

flywheel weight?

It'll make it more tractable down low but it'll still be rich.

I'd add a weight and re-jet.

GR81

31st January 2008, 09:29

sell the bike and buy my RM250? ;)

cheese

31st January 2008, 11:18

sell the bike and buy my RM250? ;)

Well it would be slower, but he would also have the problem of it breaking all the time.

quallman1234

31st January 2008, 11:22

Is the 220 a big bore version of that 200?

I have a 200 with a bills pipe on it and boy its just so smooth, i have no idea why this is called a "motocross pipe" modern 4 strokes are probably peakier.

ArcherWC

31st January 2008, 12:58

Well it would be slower, but he would also have the problem of it breaking all the time.
hahahaha....that is SO rich coming from you

cheese

31st January 2008, 13:10

LOL it was more of a dig at Suzuki than anything.

Jeremys bike is in good order and runs well.

F5 Dave

1st February 2008, 14:47

What is the pipe? Most will be aimed at better overall performance, some at midrange. No one will make an MX pipe for a kdx. Stock pipe on 220 esp known for being crud & super heavy to boot.

Strongly suspect that jetting is so rich that it just bogs real bad until finally it is spinning enough to burn through the rich mixture. My kdx was so badly jetted it felt like that when I got it.

Have a look at the justkdx website, lot of good info there & jetting is a good starting point (well was on my 89). Never ever fouled a plug thereafter.

Buddy L

1st February 2008, 17:26

Strongly suspect that jetting is so rich that it just bogs real bad until finally it is spinning enough to burn through the rich mixture. My kdx was so badly jetted it felt like that when I got it.

.

I had a 1997 KDX 220 (jap import steel tank)
and it was also badly jetted, would bog real bad and had to slowly wined on the trottle to go anywhere or it would coff and splutter:angry2:.
ended up going down 3 sizes in the jetting (can't remember the the number sizing sorry)
and transfromed the bike. crisp and smooth off the bottom and ran clean as well.
Also had the standard pipe on the bike.

FROSTY

1st February 2008, 17:40

marks

2nd February 2008, 07:32

I went back up to mangawai yesterday. I've come to the conclusion that the problem isn't the KDX its the Kind of riding I'm trying to do on it. The track(s) I've created are deliberately very tight so the boys aren't able to get up to even full speed on their 80"s.
I took the KDX to the "other side" of the forest and marked out a 2km track for myself. Heaps better and the bike feels much happier.

what oil ratio do you run?

We use my sons KDX in really tight stuff and it gets "boggier" as the day progresses - doesn't foul the plug - just gets unhappy and wont idle for long etc. We run synthetic oil at 32 to 1 which I suspect is too rich. It may have got worse since we stuck a stocking over the top of the derestricted airbox.

FROSTY

2nd February 2008, 08:14

On advice Im running 50/1 for this stuff.

Reckless

2nd February 2008, 10:48

flywheel weight?

Yep that gets my vote as well best $100-00 odd, anyone can spend on a 2 smoker!!

cheese

2nd February 2008, 12:19

Ring the Tjebbe

dammad1

2nd February 2008, 18:17

what oil ratio do you run?

We use my sons KDX in really tight stuff and it gets "boggier" as the day progresses - doesn't foul the plug - just gets unhappy and wont idle for long etc. We run synthetic oil at 32 to 1 which I suspect is too rich. It may have got worse since we stuck a stocking over the top of the derestricted airbox.

I ran 32:1 on my old KDX and never had any problems, if the plug is getting a bit dirty then you may just need to lean it off slightly.

quallman1234

2nd February 2008, 18:30

I run 30 to 1, In my KDX 200 03'. Seems fine. Only problems i have is if i drop it, its a bitch to get started again. But thats nothing to do with the oil/fuel ratio!

Then again i am pretty much thrashing the whole time nowadays! :lol:

Taz

4th February 2008, 08:11

flywheel weight?

Unlike a MX bike the KDX does not need anymore weight on the flywheel.
Great bikes for trail riding.

F5 Dave

4th February 2008, 08:26

Yeah, don't confuse oil ratio with Petrol to air ratio.

However putting in less oil will make it slightly richer.

I wouldn't go less than 40:1. Kawasaki's electrofusion isn't as robust as other manufacturers.

A properly jetted kdx will potter around for ages without fouling up.

NordieBoy

4th February 2008, 08:33

Unlike a MX bike the KDX does not need anymore weight on the flywheel.
Great bikes for trail riding.

If any bike feels peaky then wouldn't a flywheel weight help?

F5 Dave

4th February 2008, 08:49

Enduro bikes have much larger flywheels than MX bikes so there is no where as much to gain. However on the KDX websites some owners swear by adding weights to kdxs. Preference I guess.

marks

4th February 2008, 09:44

If any bike feels peaky then wouldn't a flywheel weight help?

sounds logical to me...

steahly weight for kdx (http://www.steahlyoffroad.com/weightsdet.php?s_partnum=609_)

SK1TZ

12th August 2009, 20:43

Sorry for the Thread Hi-Jack, but I am looking at getting a Trail Bike again (have been off bikes since I was about 17) and way back then all the cool trail riders my age had Daddy buy them a KDX and I always wanted one. I rode a 220 when they first came out, and although it was cool and new, it felt very "Broad" in the power band delivery, not so "Ning-niiiing" of a YZ I once had a try on.

I ahve always ridden ER185s, and xt550s (GrrrRROOOWLL) in the forests etc and on the school rides in Blenheim and i now have the opportunity to maybe get a 1999 KDX220 which is an "R" model, are these not equipped with lights etc standard or what is the "R" meaning. I am yet to view the bike, it has just come to my attention that a family member has it and really just wants it gone, so I may be in for a Bargain.

Pro's? Cons? sorry, I know I am new here, but didnt see the point in starting a new thread just for my measly rantings...

Cheers

Sam

PS, Do they Wheelie easily? I spent a lot of time on my back at 25kmh on the roads around Seddon and Blenheim as a kid, hehe, good times

Buddy L

12th August 2009, 21:09

Ive never heard of their being an "R" model of the KDX range but i could be wrong. If their is no lights on the bike i would say the lights have been changed for a KX number board.
If anything the "R" will most likely be a go fast sticker.
Like Dad's KLX300R
R might stand for relibale

flyingcr250

12th August 2009, 21:11

Ive never heard of their being an "R" model of the KDX range but i could be wrong. If their is no lights on the bike i would say the lights have been changed for a KX number board.

If their is an "R" model then maybe this is the ultamite Man made machine.

i had a KDX 250SR

SK1TZ

12th August 2009, 21:17

I did find a few pics on Google Images of Said 220 R's but I was just really wondering, shouldnt ALL KDX's have at least a Trail Light? I was hoping to fit an aftermarket Hi Output set up later on down the track...for when I cant be assed going home when the wife wanted me to...hahaha:spanking:

scott411

13th August 2009, 12:07

the KDX220's that were sold in NZ were all R's, infact all the off raod KDX200's are R's, there were street models sold in come countries, and they were oil injected rahter than premix, plus alot of other mods,

KLX300's are the same, the road legal model's were not sold in NZ,

theblacksmith

15th August 2009, 08:12