Mike McGlade

Member
Jan 13, 2000
57
0
Has anyone else been able to crack the throttle while crusing in 6th gear at about 3/4 RPM and do a wheelstand? My 98 220 has been running like this since I had the engine done at Fredette's and it is truly a thing of beauty. I feel like I'm riding my old 81 Maico 490! He ported the cylunder, milled the head, installed a Wiseco piston, bored the carb up to 36 mm then I installed boysen reeds and jetted it to near perfection and man, what a difference! Scary fast compared to what I was used to. It already had the FMF rev pipe and TCII silencer. It is also able to climb a snotty or rocky hill lugging all the way for traction in 2nd or 3rd gear. I couldn't be happier with the results of the recent modifications and if anyone is thinking of selling their KDX for a faster bike, do yourself a favor and consider the mods I mentioned. You won't be disappointed.
 

kdxman24

Member
Jun 9, 2003
10
0
I have a 99 220, and while cruising if I crack the throttle my bike will only wheelie in 4th gear. I have just put on an FMF Gnarly w/PCll and noticed a huge difference. I also have the Boysen Rad Valve coming in the mail, cant wait to try it out. Thanks for the feedback on Fredettes porting and carb boring. Now when I freshen it up this winter I will send out my cylinder and carb to F.R.P. Thanks for the info.
 

procircuit21

Member
Nov 19, 2002
125
0
What is the best money-to-performance-gain modification you can do? Porting, carb boring, what? I already have full FMF exhaust, RAD valve & new reeds on the motor. I am looking for a little more power. How about one of those Power Now things? I hear they offer performance gains comparable to exhaust systems, but that was on a 4 stroke i guess.
 

TVRider

LIFETIME SPONSOR
Oct 29, 2002
356
0
A 'Power Now' is device place between the carb and the reeds. It is a throat with a horizontal divider plate. At throttle openings below 1/2 it cuts down on the effective bore of your intake and acts as venturi to ram air/fuel into the cylinder at a higher rate. This results in more low end power. At throttle openings greater than 1/2 you have the entire bore and more normal results. That's the theory at least. I can't say if it actually works as I have never tried one. If you send your carb to RB Designs they add a similar device as well as boring out your carb to 36mm, cleaning up the throttle valve, jetting, etc.

Tom
 

Jim Crenca

LIFETIME SPONSOR
Mar 18, 2001
509
0
R&B Carb mod made a huge difference on my bike, but am now considering porting and head mod after Mike's post. How much was porting, head work, piston, & re-plating of cylinder? I'm assuming cylinder has to be re-plated after porting.
 

Mike McGlade

Member
Jan 13, 2000
57
0
You know, I can't remember exactly but it was quite reasonable as I recall. I had some clutch problems that he fixed as well and I think the total was around $450.00 or so. I don't think my cylinder had to be re-plated though. I rode yesterday and again, the bike amazed me. No trouble staying up with WR 250F, KTM 300 for example. And as I stated before, the bottom end has improved as well. You can call Fredette for current pricing-708-946-0999
 

canyncarvr

~SPONSOR~
Oct 14, 1999
4,005
0
re: plating and porting

Some more 'parroting of someone else's ideas' (gee..it's terrible to actually learn something, aint' it?):

Common sense (and the experience of some others) will tell you that if you grind on a cylinder after it's been plated, you run the risk of the plating peeling. Maybe it will happen to you...maybe not.

If it does happen to you, that means it's happened 100% percent of the time to you and your bike. Kind of like the 220 oem piston problems. Fattyk's failure rate (for example) is 100%.

Don't confuse the 'power now' divider with what RB Designs does. It's not the same thing. If you have a question, ask RB about it HERE . Do some research before you decide.

Oh...it's primarily input from sage that I'm referring to in regard to porting and plating. Understandably frp's history and resume is excellent, also. Just consider there are other points of view.

One more thing (from the archives of 'parrot talk'). Be sure that whoever does your machine work clearly understands what fuel you intend to use. It's configuration of the head that will dictate your fuel requirements. You're going to be unhappy if, having not made your intentions clear, you find you can't get away from detonation in your newly ported/head-reworked bike with your choice of pump gas from the corner station.
 

kx200

Member
Feb 1, 2001
171
0
Maybe he’s running 11-59 sixth-gear wheelies would scare me to death in the woods Jeff did my old 89 200 and it still runs strong.
 

Mike McGlade

Member
Jan 13, 2000
57
0
I have a 13/49 combination. And carvers point about the fuel is a good one. I did advise Jeff that I run pump gas( 93 octane) before he completed the mods.
 

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