what mods next for my 220? Need 220 expert advice

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firffighter
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what mods next for my 220? Need 220 expert advice

Post by firffighter »

I bought this KDX 220 after owning 2 KTM 200's and a KDX 200 with RB mods. I bought the 220 because I want a tractor 2-stroke. I ride tight Western Oregon singletrack with steep hills, ruts, roots, rocks, and slime. I need a bike to be able to tractor through the mess.

I currently have my 220 torn down with new Weisco and a fresh set of Boyesen reeds ready to go. The bike has a PC platinum pipe, airbox lid removed, UNI filter, and 13/50 gearing.

My question is to maintain this bikes great torque, should I leave it as is, put on a KDX 200 carb, or go with the RB mods. Remember, I dont want a screamer, I have already owned them. I ride my 2-strokes a gear higher most of the time for maximum traction, so giving the 220 more revs on top does not do me any good, that is why I have sold the KTM's to go with the 220's famed torque.

I have also considered a EFM autoclutch for the technical stuff, but some have said that it works best after RB mods. Is this true?

Also have considered a flywheel weight. I have one on my KTM and it did improve the tractor ability of that bike.

Looking for all of you KDX220 guys to chime in and give me your impressions on the 220's behavior pre and post mods.
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Colorado Mike
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Post by Colorado Mike »

I have a 220 and used to have it rigged like a tractor. For a pipe, normally I would tell a 220 guy to get a rev pipe because 220's are pretty gutless on top. In your case it sounds like the woods pipe would be the ticket. I don't use the flywheel weight, but lots of folks swear by them. I would definitely go with the RB mod on your stock carb, and have Ron get the most compression out of your head he can, for your altitude and fuel choice. Also, if you can swing it, check out the V-Force 3 reed block, I never heard of anyone being dissatisfied with that. I noticed a good improvement from it. I dropped a toof on my front sprocket, and use the stock rear.

I never tried the autoclutch, skipro is the expert on that.
I swapped over to the Rev pipe from the Woods, and like that a bit better, slightly more hit, but noticeably less low end. still very tractable though.
I use the stock silencer, would like to try a turbinecore.

Overall, I like my bike but think it has too little top end. It is very easy to ride though, and my kid really likes it in the woods. Seems he's always finding a reason that his bike is unrideable out there, and I end up on it. His bike flies if the trail opens up a bit though :supz:
Mike

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'04 KDX220
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Colorado Mike
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Post by Colorado Mike »

oh, missed the pre- and post part. Pre mods, I was wondering why I bought a girls bike. Post mods I was wondering why Kawy didn't build the bike like this in the first place, and why I spent so much money and time for a bike when I could have bought a used YZ250 and put a few hundred into making it trail-worthy. :rolleyes:

Oh well, it kept me out of the bars...

Wait, now it's all done and I'm back in the bars... :blink:

I like it though, it does most everything pretty well, sux at very little, and those things it sux at, I shouldn't really be doing anyway.
Mike

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'04 KDX220
KarlP
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Post by KarlP »

I personally like the stock gearing (13/47).
When I tried 13/50 I found that I lost some bottom end advantage; I'd have to shift too soon to keep it in the bottom end pulling area.

BE A LITTLE WARY OF THAT STOCK SILENCER.

I put the RB mods on my bike because I thought my suspension and skills were SO improved that I needed more power. What really happened was that my stock silencer had slowly clogged up to the point that I was frequently using full throttle.
When I got the RB mods installed, the bike wouldn't run worth diddly. Ron B helped me diagnose the problem and I replaced the silencer. Then It hauled butt!

I can't offer a "before and after" opinion on the RB mods, due to the above experience. I do know my bike runs real good with an aftermarket silencer and the RB mods :supz:
'08 KTM200xc
'99 CR/KDX Hybrid with that RB stuff done to it
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SteveWR450f
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Post by SteveWR450f »

I also live in the NW. Ride mainly at the Nestucca Trask Carlton riding area. Lots of slippery root filled rocky hill climbs.

I have 2 220 KDX - for my son and I.

After 2.5 years of owning the bikes and modding them here is what I did:

- KXF 250 forks on both
- Scotts stabilizer on both
- FMF Rev pipes
- RB carb and head mods - on my bike I have the striker carb.
- Stealthy Flywheel weight on both - Medford, Or company
- 13/49 gearing.

Run trials rear tire during some summer months. Use bike for poker runs. Both bikes tractor and hard to stall. Flywheel weight helps = better traction when it gets wet, bike also kicks easier and restarts easier when dumping the clutch.

When Spring comes and the riding area is not snowed in, you are more than welcome to try my setup. Live in Newberg
WR sold. Now have 03 and 04 KDX 220s.
KXF 250 forks. RB Carb and Head. FMF rev pipe. Long live the KDX !!!
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kawagumby
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Post by kawagumby »

I like the flywheel weight on mine. Hooks up better w/o the constant wheel-spin. The RB head mod gave it more poop just off of bottom on into mid and up some, but did not help grunt right at bottom (it actually lost a bit, but not significant IMO). I'm using the stock carb. On my bike the head mod helped reduce that hard-to-eliminate little blubber that always comes on when you're running right off of idle, so it gives a little more control in tough situations even though some off the very bottom kick is reduced.
Re: the stock silencer - I've run the stock units on all my KDX's without one ever plugging up, one with 5 seasons of high time. - so I dunno if they are a generic problem. I like the facts that I don't have to pack them, they take a lot of physical abuse, and tests I've seen for aftermarket units show they don't add more power than stock so's I can save the money to buy a better guitar someday.
1994 KDX200, Beta 200rr, yz125, yz250, kx100 modded for adult, gasgas contact 250.
KarlP
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Post by KarlP »

Yeah, I've never heard of anyone else's plugging up, either. Mine did, though. Nothing but single track? I dunno.
The aftermarket silencer didn't add diddly to the performance, IMO. I did have another stock dilencer that was good, so I can make that comparison.

On the carb, I don't think the larger bore of the 200 carb is what you're after. The RB modded 220 carb IS bored, but a divider plate is installed to help it act like a small bore carb.

Can't really comment on the clutch. I've ridden a few. I like the additional level of control available WITH a clutch.
'08 KTM200xc
'99 CR/KDX Hybrid with that RB stuff done to it
KX100 for the boy
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Jeb
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Post by Jeb »

Here's the progression of mods I made on my 220, maybe the descriptions will add to how others have commented.

I've had a rev-profile pipe on the 220 for most of the time I've owned it. As you would expect it helped tremendously overall and stretched the high end a bit.

Some time after, the RB mods I added made a very big difference. 'Got both the carb and head mod initially. Nice changes in both power and throttle response. Linear power. Great low end with plenty of torque, and seemed not to flatten out at the high end as abruptly. Revved better.

Installed a Pro Circuit Type 296, seemed to add a little in the mid-to-high end if I remember. Not very much, but it was noticeable if you were midrange and snapped the throttle open.

I changed gearing from stock gearing to a 12/47 combo. Revved even better. Still maintained great traction.

I wanted more power so I sprung for Ron's modded head shaped for race gas. That's when the bike starting getting downright snappy, right off the bottom. More power throughout but still not something that'll bite ya too easy. The revs would spin up very quickly (like an mx bike) but still linear-like. AWESOME throttle response (started to get a little twitchy in the tight stuff but not intimidating). I was zipping through gears like you would with a 125 and screaming almost like one, great acceleration. Lifting the wheel a little became even easier yet still controlled. Retarding the timing improved the high end even more, didn't notice the low end being impacted significantly. Matter of fact I decided to try gearing it up to make better use of the power.

Last mod was going to a 12/45 combo (somewhere's between 13/47-stock and 12/47). I haven't given it a really good run for the money because I'm recuperating from knee surgery but I ran it a couple of times in our back yard (big yard) and liked how the newer gearing stretched out the shifting a tad. Best I can tell I'm nowhere near dulling the low end - got a strong pull to it right off the bottom.

Last comment. I've ridden the KTM 200 before and even with the rev pipe my RB-modded 220 will out tractor those things hands down.
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firffighter
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Post by firffighter »

Thanks for the great input so far. I have a Pro Circuit silencer as well, guess I forgot to mention that. I thought that most would steer me towards the RB mods. When I did them to my '92 KDX200 I loved the results and I felt it made tha power totaly linear with nice crisp smooth throttle response throughout. I just dont want to end up with a bike that needs to be revved out to perform, since that is what I just got rid of and that is also why I bought the 220 because it was known for such great torque.

Steve, did you feel like your bikes needed to rev more after you RB'd them? What was the result in performance after you RB'd. Did you notice any difference in being able to run a gear higher after the RB. I am not looking to gain much on the top end since you know that most of the time we are running 2nd and 3rd gear in the Trask and the Burn.

Here in our Oregon terrain 13/50 gearing is a must, and I have run it on my other KDX, and both KTM's with good results.

The only reason I am considering the autoclutch is that if I were to do the RB mods and put on a FWW, it would be nearly the same price as the autoclutch. From doing some research it sounds like the autoclutch would be amazing for the type of terrain I have described.

All of your advice is greatly appreciated, please keep it coming.

BTW. Steve, did you get your extra rear wheel for your trials tire?
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xagentman
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Post by xagentman »

After doing the RB mods I can say that it had better low end and improved throttle response. The reason for this is the divider plate that Ron installs. While he opens up the carb for a stronger top end the divider plate acts as a smaller carb for an incresed low end at half throttle and below positions. Lots of guys here talk about the SSS or the second sweet spot on the RB moded carbs. I would read up on their experiances.

One thing that I can say is RB mod on 220 = more torque not less.
==05 KDX220R==
SteveWR450f
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Post by SteveWR450f »

Same as above. RB mods gives you better low down because of the divider plate and head port. Get better upper because bigger bore of the carb.

With my setup, I typically ride in a gear higher than other guys on their bikes. Had a friend who rides a RM 250 2 smoke. He tried my bike. He did not get it at first about riding in higher gear and lugging it more like a 2 stroke. After a few trails, he figured it out and now wants a bike like mine. He said you can ride longer - less fatigue - and have better traction because your rear tire is not spinning. I agree.

Yep, about the rim. Now have spare rear wheel with trials tire mounted on it.

Do the RB mods, you will love it.

For the money, its the best engine mod in my opinion.

I forgot to mention that I really like Vforce 3 reeds. Good throttle response.
WR sold. Now have 03 and 04 KDX 220s.
KXF 250 forks. RB Carb and Head. FMF rev pipe. Long live the KDX !!!
firffighter
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Post by firffighter »

I know that the RB mods would make this bike even better than it is, and in combination with a FWW and a trials tire, it would be killer in the terrain I ride in. But, for some reason I am intrigued by that autoclutch. I know the Endurocross crowd are running them, and from everything I have read, they make life much easier in the nasty terrain. Maybe I will do both after taxes come back. No stalling, constant traction, less arm pump, and the ability to trully ride a gear higher are very attractive features of that autoclutch.
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Post by AZRickD »

I switch my PC Plat II torque pipe and my FMF Gnarly rev pipe every other month or so depending on conditions. Usual day in single track or a technical race and I put the torque pipe on. If we have a more wide-open race (with technical parts), I give the rev pipe a go.

Perhaps I don't have it jetted properly for the rev pipe, but the extra 1,000 or so RPMs (measured through Trail Tech Vapor) are found only in the first three gears and it diminishes quickly to no bonus in sixth gear and top speed (75mph).

That said, I really like the bike better with the torque pipe for my riding.
I done KX-ed QuailChaser's KDX220R
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