KDXRIDER.NET

Cornishwrecker posted this back in 2009:

"Speed is just a question of money......

How fast do you want to go !
Yep RB head & carb mod will make your kdx run well...... But nowhere near as well as a full port job with added head & carb mods.
My 220 has had a full port job done with the head squished, jetting dialed in on a dyno & running a 36mm carb off a kx 125, boyesen rad valve with modded air box, timing adjusted & all breathing through a full FMF 'woods' pipe...... My bike just puts out shy of 40 bhp at the rear wheel, now you may think that with all these mods my bike runs like a mx bike but you'd be wrong, for the power delivery is very smooth with lots more bottom end pull , a healthy mid range plus a few extra rpm over run ....that's what I asked for when I spoke to the tuner & that's what I got....
So to answer your question .... Go to fredette & get the full works ."

Looks like he has his PMs turned off so I'll throw the question out for discussion:

What is the maximum horsepower/torque that anyone has documented for the 200 or 220? Does anyone have a dyno run chart available? (Be sure to specify which model and what mods you have completed to achieve your results.)

L

hardly anyone has run their bike on a dyno so I doubt you'll get any responses

A KDX and a dyno.

Without a baseline run on any bike, it is hard to compare. Different dyno's will give different results. If one were to show a screen shot or printout of before mod and after mod, then that would be useful.

If you want a narrow powerband, screaming demon, top end drag racer, then it is possible to get more power eek'ed out than normal mods. Look at what 125cc two-stroke GP bikes did, 50 or so it seems.

Here's a copy of one guy's old post from another forum...the link to the dyno run is no longer valid.

"I've posted a current dyno run at my site, this is with a FMF Rev & TC II, 38mm Plated carb & pump gas. I've got a full Pro Circuit system coming an I'll post a run with that system for a comparo. heres the link - Dyno run, 99 220" Peaked at 36.4 HP.

FWIW I had a 220 set up similarly, with RB head and striker carb and seat-of-the-pants was upper 30's, no problem.

peak horsepower ratings on dirt bikes... about as important as what color valve stem caps you use.

True, but its still fun to know. There is a dyno in the auto tech shop at my daughters high school. I want to get by there with the bike before she graduates this year. She didnt take auto tech this semester as she couldnt fit in in, but she is in good with the teacher. They have a seriously impressive shop up there! Im guessing with RB head and carb, DG exhaust, no airbox lid, and a fresh-ish full rebuild, I might see mid 30's.

That sounds like a reasonably normal set up Julian. Mid 30's would be nice and for the most part peak will be similar and the variation in the curve.

Julien D wrote:True, but its still fun to know. There is a dyno in the auto tech shop at my daughters high school. I want to get by there with the bike before she graduates this year. She didnt take auto tech this semester as she couldnt fit in in, but she is in good with the teacher. They have a seriously impressive shop up there! Im guessing with RB head and carb, DG exhaust, no airbox lid, and a fresh-ish full rebuild, I might see mid 30's.

look for ways to prevent wheel spin, that's where da gold at. ;-)