220 Fredette Power Delivery - How smooth?

[KTM Mike]

Hi all. I have been lurking around here trying tohide my orange blood ;) trying to learn about KDX's. But it looks like I will have to let it show for a moment!

I have decided to buy a KDX for my son to step up to from his TTR-125. One reason I chose the KDX (200 or 220) was how smooth and manageable the power delivery is known to be.

I just came across a used 220 that was worked over by Jeff Fredette - milled head, ported, carb bored out, FMF Rev pipe, FMF silencer etc. From what I understand, these mods really wake up the 220. Also, i understand the larger carb trades off bottom end for top end. Certainly, after my son improves a bit as a rider, all these mods may be exactly what he needs, but to start with he will need smooth delivery.

So - what could I expect out of this modified 220? Is the power going to come on hard and fast :yikes: , or still nice and mellow? :ride: A buddy of mine had a 220 with the Rev pipe, and he felt it had a HUGE impact on the power delivery - much more sudden (still compared to a full on MX bike, smooth...but much less so)

I was planning on a flywheel weight regardless (was going to do that even with a stock motor), and in this case would consider putting on a stock pipe and silencer to choke things back down a bit (I know...what a shame...but I gotta keep my son's skill level in mind - there will be plenty of time for him to rip on it after he is more familiar with it!). Will these two steps take the hit back out of the bike?

Your thoughts appreciated!

 

[89kdx200rdr]

its awful

 

[89kdx200rdr]

put him on a ktm

 

[Rhodester]

The Rev pipe on the 200 puts a significant hit in the power band (the torque pipe has no hit, just more power everywhere over stock). I don't know how the powerband (hit-wise) is effected by the Rev pipe on the 220.

 

[Mainekdxer]

I put a REV pipe on my '00 220, and the power change was significant! To say it woke the bike up would be an understatement. Lowend - mid range - topend were all increased. The power delivery is still smooth and manageable, but it is a big jump over the TTR. I have a TTR 225 (for my wife) and that has a very forgiving power delivery, but is in no means comparable to the 2 stroke KDX. I just had my top-end worked on by Fredette and expect to get my engine back this week. Jeff says that the power change is similar to the one after the pipe change, so I am expecting a big difference. By putting on the old pipe and silencer back on I would imagine you would quiet it down quite a bit. If you need a stock pipe and silencer let me know I have my old one kicking around.

 

[Smit-Dog]

FWIW, I rode the KDX 220 that was owned by Fred T, and now Sparky. It has an FMF pipe, not sure which one, but that bike was a rocket compared to my stock KDX 220. BIG difference.... the front-end liked to come up.

Coming from the TTR 4-stroke, the 2-stroke is going to be somewhat of an adjustment as it is. I would lean heavily towards a stock KDX, and go from there. Is the stock pipe still available to cork it up a bit? You're going to want to lean towards having some decent low-end as the priority.

I believe that Badgerman's son Ian has a stock KDX (engine-wise). Maybe you can let Mark take it for a test ride when some of the snow melts.

 

[KTM Mike]

Well it looks like that Fredette 220 is no longer under consideration.

We are now heading towards a 200 that will come with 3 pipes! Fatty, Burly and Stock, and two silencers, FMF TCII and stock. So i can cork it up to start with, stick the a flywheel weight on as well. Then uncork it with the other pipes later on. It was a lucky find to get a bike with about all I will need to spice it up included in the deal!

Maine - thanks for the offer of the pipe - I will let you know if I end up needing one!

 

[john_bilbrey]

Don't the 200s have a more pronounced hit than the 220?

 

[KTM Mike]

From what I have read, yes they do. That is why I was leaning towards a 220 - hopefully a bit smoother. But, I came across a deal I just could not pass up on a 200. I think that with a stock pipe and silencer, and flywheel weight, maybe mess with some jetting if it needs it, I can tame the hit down enough to be managable for my son.

Smit Dog - I didnt realize your 220 was a former Fred T scooter! I wrestled at length with the issue of Mark coming off a mellow 4 stroke onto a two stroke, but the weight of the 4 strokes that would in any way seem appropriate for physical size wise him ruled them out compared to the KDX.

 

[Fred T]

From what I have read, yes they do. That is why I was leaning towards a 220 - hopefully a bit smoother. But, I came across a deal I just could not pass up on a 200. I think that with a stock pipe and silencer, and flywheel weight, maybe mess with some jetting if it needs it, I can tame the hit down enough to be managable for my son.

Smit Dog - I didnt realize your 220 was a former Fred T scooter! I wrestled at length with the issue of Mark coming off a mellow 4 stroke onto a two stroke, but the weight of the 4 strokes that would in any way seem appropriate for physical size wise him ruled them out compared to the KDX.

No mine was scooped up by SPARKEY, bill had a 2002 that was a stocker. My old one had everything you can imagine done to it.

 

[Smit-Dog]

Sorry for the mix-up... what I meant was that I took Fred's out for a brief spin around the clubgrounds. Fred sold it to Sparkey, and I had another chance to ride it at the Stump Jumper in Wolverine. It was a rocket compared to my stock 220. Hard to believe one was just a tuned/hopped up version of the other.

My stocker was sold to miScott last winter.

 

[KTM Mike]

Actually - it was my mix up! All you said was you RODE Freds bike...not owned it!

Boy, all that was begining to sound incestuous almost!

I think what the performance difference demonstrates is the real potential of the KDX - something as little as a pipe etc, making such huge differences. (though I suspect Fred had more than a pipe going on!) I have a Fatty on my 300 - and while it did make a difference, certainly not as notable of an impact as a pipe seems to have on the KDX.

 

[Canadian Dave]

Mike not to worry you can easily detune the modified KDX by doing exactly what you suggested, installing the stock pipe. If you find the power is still a little too much for your son then you could try installing a washer with the same OD as the exhaust flange and a smaller ID that the exhaust port between the pipe and cylinder to take some more power away and I'm sure you could come up with some sort of throttle stop if need be. Detuning should be no problem even in the bike's modified state.

David

 

[libskater]

with an aftermarket pipe the 200 can be a handful for a beginner. it was interesting watching my cousin ride my bike with a fatty on it for the first time. he was all over the place. but if you leave the stock pipe on its very manageable and as long as he stays smooth on the throttle at first there should be no problems getting adjusted from a mini thumper. you could always just put a throttle stop in as canadian dave pointed out. i coulda used one of those when i got back into it again from riding fourwheelers and thumpers for 4 or 5 years. but if you cant make up a throttle stop just teach him to be easy on the go wrist and he'll be ok.

 

[Tom L]

Don't forget: You can always cover up the air box as much as you want to kill the power. That reminds me! I had an old '86 CR500 that was crazy loud!!!! The silencer had about a 1" opening; so I wrapped a 4" long piece of 1/2" diameter copper tube with insulation and stuffed it in the silencer to try and quiet it down a bit. Wow!!! It did quiet it down a little bit, but took away about 75% of the power too!!! There you go!!! Just stuff something in the silencer!!!! That'll kill it!!!! :laugh:

 

[KTM Mike]

Thanks for the tips guys.

The bike we ended up with is a 99 200. It came with a stock pipe and stock silencer, a Fatty and a Burly and a TCII SA! Plenty of "tuning" options!.

I will put it all back to stock, and do the throttle limiter at first, will put air box snorkel back on, and will install a flywheel weight - both for smoothing out power delivery but perhaps more importantly, to avoid frequent stalling - which would be a big frustration for him I am sure!. My son is OK with throttle control (I think?). After a bit of time like that, we will slowly remove the various "limiters" and bring him back up to "full speed". Now, I may be 100% totally making something outta nothing with all this. My kid may jump on this thing like he been on it for years, making me feel like the slow old fart I really am!

My next issue will be spring rates. The bike came with .41kg front springs, which I will be trading off to a friend for some stock springs. The rear on it is stock (not sure what rate that is?). My son is about 135 without gear on. Perhaps the rear will be OK stock - but that is another thread i suspect!

 

[Rhodester]

Stock rear spring is a 5.0 kg. I'm 225lbs. and it works great for me. Your son will want something softer.

 

[m0rie]

Hey KTM Mike i'd swap you the rear spring from my 89 KDX 200 for the rear spring from your 99. Its a 4.8kg weight spring vs the 5.0kg spring in your 99. That would put the spring rate a lot closer to the optimal for a 135 lbs rider.

-Maurice

 

[KTM Mike]

Hey KTM Mike i'd swap you the rear spring from my 89 KDX 200 for the rear spring from your 99. Its a 4.8kg weight spring vs the 5.0kg spring in your 99. That would put the spring rate a lot closer to the optimal for a 135 lbs rider.

-Maurice

Maurice - shoot me an email at sstephenson@i2k.net. We may be able to work something out! Are you certain a 89 is compatible with a 99?

I dont have a feel for how significant of change a 4.8 is vs a 5.0 - is that the first step down in rate, or is there like a 4.9 etc? Or should I be shooting for lower yet?

One thing that just came to mind though - if that kid of mine keeps eating and growing like he has been lately - I will soon want a 5.2! Either that or he will demand I relinquish my 300 EXC to him!

 

[KTM Mike]

Ok I answered my own question on rear spring rates - I took a look at Fredette's web site. Yep..89 to 04 sameo sameo.

>>>>>>>> From Fredette's web site:
1995-2002 "H" Models: The stock spring seems to work well for riders that weigh between 180-210lbs. I recommend replacing the stock spring with a 4.6kg SPRING for riders weighing less than 150lbs, a 4.8kg SPRING for riders weighing between 150-180lbs and a 5.2kg SPRING for riders weighing more than 210lbs. The type of terrain you are riding will determine the correct compression and rebound settings. I recommend setting both the compression adjuster (located at the top of the shock) and the rebound adjuster (located at the bottom of the shock) at about 8 clicks out for faster terrain. For slower more technical terrain I recommend setting both the compression and rebound settings at about 12 clicks out.
>>>>>>>>>>>

4.8 is first step down, recommended 150 to 180 lbs. But certainly better than a 5.0 for my kid - and he could (will!) grow into a 4.8 before to awfully long! 4.6 sounds ideal for his CURRENT weight...though.

 

[Rhodester]

I tried (bought) an Eibach 5.2kg shock spring. It was way too stiff for me (@ 225lbs.). I suppose that if I was racing and could reduce my high speed compression damping more than I already have...then just maybe it'd be OK.

 

[KTM Mike]

mOrie

I havent heard back from you. I would like to swap springs with you. Email me directly as sstephenson@i2k.net so we can make arrangements.

Mike

Hey KTM Mike i'd swap you the rear spring from my 89 KDX 200 for the rear spring from your 99. Its a 4.8kg weight spring vs the 5.0kg spring in your 99. That would put the spring rate a lot closer to the optimal for a 135 lbs rider.

-Maurice