kdx 220 to rm250 to drz400 swaps

Questions and comments about converting to beefier forks..
Post Reply
ohgood
Supporting Member II
Supporting Member II
Posts: 923
Joined: 10:00 am Jan 04 2014
Country:

kdx 220 to rm250 to drz400 swaps

Post by ohgood » 02:36 am Feb 16 2019

five years ago i bought a kdx 220 for $600.

it sat in my garage for a year prior to posting for it, i just never rode it, my friend didn't care.

finally starting riding it and realized it was a great platform, but needed
more power, better forks

changed to kdx 200 cylinder/head/carb advanced timing jetting etc

swapped on a rm250 usd fork after i broke the stock kdx springs

it was awesome in third gear pinned, but i don't pin it much.

yesterday i looked at my parts bike drz and decided to swap forks.

the drz (sm) comes with usd rm250 forks (which i had on my kdx) and my drz s had conventionals (which i prefer) so i took the two hours aside and did it.

needed:
press stem from both triples
glue kdx stem into drz triple
swap forks, front wheel is the same between drz / rm / kdx
if using kdx wheel you have to change bearings to fit the drz axle
all in it took four hours because i let the loctite 680 cure for two hours.

pro:
drz forks are plush... PLUUUSH,
conventionals resist rocks better

cons:
dirty fingernails

I'll ride today and see how much better it is. 😂

User avatar
rexemouse
Supporting Member I
Supporting Member I
Posts: 24
Joined: 01:06 pm Apr 21 2017
Country: US_MA

Re: kdx 220 to rm250 to drz400 swaps

Post by rexemouse » 08:06 am Feb 16 2019

Nice upgrade. Should flex way less than the 43mm stockers. Im also a fan of conventionals, and they look better on the kdxs imo, vs the usd swaps.

Curious, why did you chose to swap to a 200 cylinder?

User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 9196
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: kdx 220 to rm250 to drz400 swaps

Post by KDXGarage » 09:42 am Feb 16 2019

Congratulations on the swap. Enjoy the ride!
Thank you, Julien D for keeping the site going.

If you have a question about YOUR BIKE, please tell us what model YOUR BIKE is. :-)

doakley
Gold Member
Gold Member
Posts: 453
Joined: 02:58 pm Mar 10 2016
Country:

Re: kdx 220 to rm250 to drz400 swaps

Post by doakley » 01:59 pm Feb 16 2019

rexemouse wrote:
08:06 am Feb 16 2019
Nice upgrade. Should flex way less than the 43mm stockers. Im also a fan of conventionals, and they look better on the kdxs imo, vs the usd swaps.

Curious, why did you chose to swap to a 200 cylinder?
I would have the same question. You said you seldom pin the 200 in 3rd, which is where it would show more power than the 220. I would have thought in that case you would be better off with the additional low end of the 220, if that's the part of the powerband you're actually using.
Just curious.

ohgood
Supporting Member II
Supporting Member II
Posts: 923
Joined: 10:00 am Jan 04 2014
Country:

Re: kdx 220 to rm250 to drz400 swaps

Post by ohgood » 05:59 pm Feb 17 2019

doakley wrote:
01:59 pm Feb 16 2019
rexemouse wrote:
08:06 am Feb 16 2019
Nice upgrade. Should flex way less than the 43mm stockers. Im also a fan of conventionals, and they look better on the kdxs imo, vs the usd swaps.

Curious, why did you chose to swap to a 200 cylinder?
I would have the same question. You said you seldom pin the 200 in 3rd, which is where it would show more power than the 220. I would have thought in that case you would be better off with the additional low end of the 220, if that's the part of the powerband you're actually using.
Just curious.
i also swapped the 35mm carb instead of the 220's 33mm.

the 220 has always felt like it needed 'something' across the rev range. i rode a 200 after repairing it for a friend, and the power of the 200 was FANTASTIC compared to what i had felt from the 220. that repaired 200 pulled very smooth and linear everywhere, instead of peaky or luggy. just better.

the forks were fantastic (drz) on the kdx yesterday. i can't wait to ride it again. they do very well in the squishy stuff (rock beds/ creeks) and medium speed (fire road/trail) was good also. i haven't been over 40 mph yet, that's just not my style ;-)

doakley
Gold Member
Gold Member
Posts: 453
Joined: 02:58 pm Mar 10 2016
Country:

Re: kdx 220 to rm250 to drz400 swaps

Post by doakley » 09:24 am Feb 18 2019

I’d check the jetting yet again, from the beginning. Also, what pipe do you have on the bike? The 220 “wakes up” with an FMF pipe and proper jetting. Just my $.02.

kdxdazz
Member
Posts: 105
Joined: 07:51 am Dec 28 2017
Country: thailand
Location: Thailand

Re: kdx 220 to rm250 to drz400 swaps

Post by kdxdazz » 10:42 pm Feb 19 2019

Great idea for a fork swap. I've found my kdx forks to be too harsh although I haven't done any shim stack adjustment yet and with the drz forks you get the adjustability

ohgood
Supporting Member II
Supporting Member II
Posts: 923
Joined: 10:00 am Jan 04 2014
Country:

Re: kdx 220 to rm250 to drz400 swaps

Post by ohgood » 06:18 am Feb 23 2019

doakley wrote:
09:24 am Feb 18 2019
I’d check the jetting yet again, from the beginning. Also, what pipe do you have on the bike? The 220 “wakes up” with an FMF pipe and proper jetting. Just my $.02.
i don't use other people's jetting numbers. i consider that a poor way to make a machine run well. it can be used as a starting point, but ultimately that's all it can ever be because of the variables like riding style/humidity/temperature/timingadvance/airbox/cylinder condition/carb used/etc

the jetting was meticulously and methodically set, starting with the float level, pilot, needle, main, and then all over again each time I made a timing/airbox/pipe/silencer change. the 220 ports simply can't produce the same kind of power that the 200 cylinder does. i'm not saying the 220 is -BAD-, it's just not as good as the 200.

here's a video with a few points that you can hear the bike through the rev range. it's very happy at lugging through rocks or WOT, for the three seconds i'm comfortable with WOT ;-) before shutting down or upshifting ;-)



honestly the drz forks are a bigger improvement than all the jetting in the world, carb swaps, or anything engine related. they do not flex like the stock kdx forks, but are so plush and smooth rolling through harder terrain I just have nothing to complain about now.

sooo, here's my top five mods

1 front end swap, specifically drz400 (post 2002 forks for full adjustability)
2 full suspension service (pivots/shock/forks)
3 timing advance per rider preference (low rpm vs hi rpm)
4 tall seat
5 all other engine /power modifications

:-)

ohgood
Supporting Member II
Supporting Member II
Posts: 923
Joined: 10:00 am Jan 04 2014
Country:

Re: kdx 220 to rm250 to drz400 swaps

Post by ohgood » 06:20 am Feb 23 2019

oh ya, also on the mod list... way down at number 500 or 600 or so:

premix oil type

followed by

premix ratio used

but that's so far down the list that "what socks should I wear" is exponentially more important :D

User avatar
rexemouse
Supporting Member I
Supporting Member I
Posts: 24
Joined: 01:06 pm Apr 21 2017
Country: US_MA

Re: kdx 220 to rm250 to drz400 swaps

Post by rexemouse » 08:01 am Feb 23 2019

With the swap, did the steering stops need to be modified? And are you running the forks deeper in the triple?

Thanks for elaborating on your dissapointment with the 220. I am currently rebuilding a 220 to replace my tired 200 engine, and I am a little concerned I will miss the 200 power characteristic. I've read every post I can find on this topic, and half of the opinions are similar to yours while others half claim the 220 revs out just fine with the right exhaust and a 35mm carb w/ dialed-in jetting.

ohgood
Supporting Member II
Supporting Member II
Posts: 923
Joined: 10:00 am Jan 04 2014
Country:

Re: kdx 220 to rm250 to drz400 swaps

Post by ohgood » 09:51 am Feb 25 2019

rexemouse wrote:
08:01 am Feb 23 2019
With the swap, did the steering stops need to be modified? And are you running the forks deeper in the triple?

Thanks for elaborating on your dissapointment with the 220. I am currently rebuilding a 220 to replace my tired 200 engine, and I am a little concerned I will miss the 200 power characteristic. I've read every post I can find on this topic, and half of the opinions are similar to yours while others half claim the 220 revs out just fine with the right exhaust and a 35mm carb w/ dialed-in jetting.
i am tapping the drz stops to accept a bolt, which will make them contact the stock kdx frame stop. that way it's easy to go back to stock drz stops on a drz or stock kdx forks on the kdx.

yes i dropped the triples about 5/8" on the forks to see if they got too 'fast' handling. it never felt twitchy at speed, which surprised me. i expected some twitchiness, it's just plush everywhere. in creek beds with rocks and free riding root / rock infested no-trails areas, it was plush. i don't think i bottomed it all day, even with stock springs and 5wt. in the video you can see where i stuck the front wheel between two rocks, it didn't bottom then.

sorry to make the 220 sound -bad- because that's not the intention. it's good, but the 200 cylinder is better. the 220 feels like it's made to just lug around, and is resistive to revving out, and/or feels like less of an engine from mid to top end, than the 200. i've done extensive jetting tests to eliminate that variable, i couldn't get the 220 to feel as linear as the 200 is. it's easier to ride the 200, because of the smooth linear power delivery. the 220 just feels like it wants to be a lugging machine and not much else. advancing the timing fully on the 220 helped, but the 200 fully advanced eats it up.

as far as free revving, i doubt you could tell a difference between the 200/220. with a load though, the 200 wins. i ran a 33 and 35mm carb on both cylinders to test.

kdx200 with drz400 (post 2004) conventional forks:

doakley
Gold Member
Gold Member
Posts: 453
Joined: 02:58 pm Mar 10 2016
Country:

Re: kdx 220 to rm250 to drz400 swaps

Post by doakley » 12:49 pm Feb 25 2019

I for one didn't think you made the 220 sound bad, just different. Actually I think you identified exactly what Kawi was trying to achieve with the 220, a low end oriented engine. No question the 200 is faster mid to top. For me though the 220 is preferred (yes I've ridden both) due to that low end lugging. If you really want it to scream, I understand Jeff Fredette can make you a 220 that will shame most 250's. Just not what I was looking for.

Post Reply