KDX more linear power delivery

[SADude]

Hi I have a KDX 200 and I am looking to improve the power delivery of the bike, without modifying the engine. I currently run the bike with the air box lid off, a Powercore 2 silencer and a gutted header pipe, but will be looking at fitting a FMF Gnarly wood pipe and Boysen reed petals in the next month. Will this help give me a more linear power delivery? I like the two stroke power surge, but sometime when it gets wet it is nice to be able to putt putt around at lower RPM up hills and over rocks.

Thanks

Paul

 

[KTM Mike]

If it is much more tractable power and resistance to stalling etc at low speeds you are after, consider a flywheel weight. I recently put one on my KTM and absolutely love it! You cant hardly force the bike to stall when slogging along slow in nasty conditions - it just keeps on chuggin with out stalling! Traction seems to hook up way better with less wheel spin, yet it still has plenty of 2 smoke snap. I installed one on my son's KDX based on this - though I have not ridden it yet with the weight on. A 200 may or may not respond as well as my 300 did though.

 

[bradf]

Call RB Designs (503) 645-2607 Talk to Ron Black.

 

[Rhodester]

I like the fly wheel weight. The difference is subtle, but an improvement. I don't know what you've done jetting-wise, but a Cxx needle will soften the bottom end snap over a Dxx needle. I love the -35 (Gnarly woods) pipe. It gives the bike nice hitless linear power, but tons of it when the bike is jetted properly.

 

[MY KDX 220 R]

Nice to see someone from Maritzburg on this forum, I'm relatively new here.
'Been in the States for a while, origionally from Northern Natal and The Lowveld.
Used to ride 200 KDX back home aswell.
Send me an e-mail if you'd like to compare notes.
Rod.

 

[SADude]

Thank you for all the replies. I was looking at using the following jetting once I got the pipe: 155/48 or 155/45 with the standard needle in the second clip, any input here would be great.

Rod, it is good to hear form a fellow South African. I would really like to compare notes, how do I get you email address off this site?

Cheers

Paul

 

[chris kuba]

Try using Active reeds. They are carbon fiber and last much much longer than the Boyesen jobs. They also work better. They cost about $60 with shipping. They can be purchased through the Twin-Air filter company. You won't be disappointed.

 

[MY KDX 220 R]

Paul, use - rodney chaplin 8 @ aol .com

 

[SADude]

I take it that the email address is all on word. Will Mail you shortly.

 

[SADude]

Hi Rod

I sent mail to [email protected], if the mail doesn't arrive my email address is [email protected]

peegreen, thanks for the input, I will do a search on it.

 

[John Harris]

All bikes are different for jetting, but having a leaner pilot will help smooth the transition and hit. I think a rich pilot causes the engine to have to burn out the surplus fuel mixture as it transitions to the main jet and causes hit. I believe you will like a 42 pilot jet much better than a 45. My conditions and KDX modifications are different from yours, but I have been happy with a 40 pilot. My experience has been that engines do not sieze at low rpm so I like to run leaner on the pilot than most! Experiment to find what is best for you! Cheers John

 

[SADude]

Hi John

Thank you for the input, do you mind if I ask what setup you are currently running on you KDX?

This is My current setup:
UFO Plastics Maier Rear Fender, Pro Taper Handle Bars, Bark Busters, UFO Frame Guards, Hyde Bash Plate, FMF Powercore 2 Silencer, Removed Air Box Lid, Fork Guards (PVC Pipe), Armadillo Header Pipe Guard, 10 Weight Fork Oil, Guttted Standard Header Pipe, 0.37kg/mm Fork Springs, 49 tooth rear sprocket, FX Seat Cover.

Things to come:
Boysen Reed Petals, Re-jet Carb 155/48 or 155/45, FMF Gnarly Header Pipe, FX Graphics, Graphics Clear Protection Sheet.

The Reed Petals and the FMF Header Pipe will be done within the next month.

Any input is always welcome.
Cheers Paul

 

[Knetman]

Does anyone know the specs of a 1997 KDX200 (H3) flywheel weight?
My bro in-law is a machine maker so might be able to get him to make one...

Otherwise, does anyone know where I can get one in Australia and their approx cost?

Thanks all!

 

[SADude]

Well I have fitted the FMF Gnarly pipe and the Boysen reed petals and I am very happy with the results. It has made the bike alot more responsive and has improved both the bottom end as well as the top end power. My jetting is as follows, 160/48 with the needle in the middle clip and the air screw one and a half turns out.

 

[Rhodester]

SADude, your jetting is stock. It should be acting richer now than before the pipe and reed change. I'd definitely start out with a 155 main and 45 pilot and fine tune from there (assuming that you're near sea level).

 

[slcyclerace]

Here's a reprint of my recent post on another thread in this forum. If you've already read it, just skip to the next paragraph.
I finally have my KDX to where I want it but I wish I had followed Jeff Fredette's advice and I probably would have saved some cash. I went with a Pro Circuit pipe and a PC spark arrester as well, I installed a Boyesen Rad Valve at the same time so I can't say for sure which one made the biggest difference but the power delivery was kicked up several knotches in the low end area without losing much on top. I went to a 12 counter sprocket and that gave me even more down low and I really didn't care about losing a bit on top because tight woods around here aren't a top gear priority. The airbox cover is now just a shell and I threw in a Uni Filter since they're supposed to be more free flowing. My jetting for warmer weather -I went down to a 152 main and a 45 pilot, opened the air screw to about 1 3/4 turns out and went down one clip on the stock needle. You'll have to jet for the conditions in your area but that's what I went with for 70 degrees on up at near sea level. I change the top end every season even though I could get away with going longer, I always go with Wisco but if you're just re-ringing it go with OEM or Pro-X which is closest to stock. Don't re-ring your cast OEM with Wiseco rings. The KDX is a fun bike now and a perfect compliment to my 520SX.
I could have saved some money by leaving out the Rad Valve and just going with the Boyesen Pro Reeds. I also hear that the FMF set up mentioned above is a good choice.

IMO, after much research, I believe the biggest bang for your buck is found in porting your cylinder for more everywhere. If you have the bucks you could throw in having it bored out to 220 and having it replated. Eric (Gorr) does some fine work and you have an alternative of sending it to Jeff Fredette. Either one will give you a superior job and service. I guess you all know the great work Eric does but here's what Jeff has to offer. Here's his line on porting.
If you still want more power from your KDX I would recommend that you SEND us your cylinder so we can work our magic on its ports. This modification will provide even greater performance throughout the power band with more revs at the top. After making this modification you may need to replace the stock jetting with a 45-48 PILOT JET and a 155-160 MAIN JET.
The KTM has such a great motor that I wish I could swap the suspension with my 520.