KDXRIDER.NET

Thanks, me too. Gotta be careful with these cheap older bikes, and like em enough to dump $$ into them. I bought my 88 for $300 or $400 (i forget).

$500 motor
$ 50 reeds, aircleaner
$ 75 Chain and sprockets
$ 60 Knobby
$ 25 wheel bearings That's $1200. May as well add $450 for RB carb and head DG pipe
$1650. 99-02 KX250's go for that. Hmmmmm. I want my KDX!!

the powerband (where in the rpm range the best power is) is all dependent on both the port heights and the header length of the pipe (as well as the rest of the pipe but the header is the most important).
That being so I would lathe the base of the cylinder 1.7mm and extend the header length. Extending the length 2 inches lowers the powerband 500 RPM.
A squish band .6mm-.8mm from the piston top does wonders at limiting the heat the piston absorbs for less chance of seizure. But it doesn't lower the overall engine heat. Try a colder plug and retard the ignition by rotating the stator coil plate CCW.
see my page on increasing the powerband of the KDX200 at http://www.dragonfly75.com/moto/KDXpowerband.html

dsmitty wrote:Thanks, me too. Gotta be careful with these cheap older bikes, and like em enough to dump $$ into them. I bought my 88 for $300 or $400 (i forget).

$500 motor
$ 50 reeds, aircleaner
$ 75 Chain and sprockets
$ 60 Knobby
$ 25 wheel bearings That's $1200. May as well add $450 for RB carb and head DG pipe
$1650. 99-02 KX250's go for that. Hmmmmm. I want my KDX!!

I bought my 93 (6 years ago) for $1200, I have easily put another $1500 into parts, tires, oversized bars BLAH BLAH BLAH....The bike would sell for $1100 (around here...maybe more) if I put it up for sale......That doesn't mean that I could have bought an 01 KX and rode it for 6 years and not spent any money on it....It just means that I would have spent $2000(ish) on a KX and then spent another $1500 in parts on top of that. That's just the way dirt bike are.
If you really think about how much $$ you actually spend on a car, especially if it's financed, you'd never buy a new[er] car again!

Thanks Jag. Great info! I'm gonnna check the web site later today..I just came back to the garage for more gas..Headin back out to ride. I need as much low end as I can get. 80% of our riding is puttin through tight trails and hittin little jumps and hills from off idle. I'm lookin forward to checkin out the web sight to see if you got a few more tricks for torque and low end! Thanks again!

6 riders is right on. For me riding is a hobby and it costs $$. new bike or old. One ting I think about to justify $$ into an 88 kdx is this. I'm a little guy, bout 5'6". So I'm on my tip toes. kinda hard crossing a creek with big rocks and stuff like that. So I'm lowering it 2 or 3 inches and I'm cutting another 2" off the seat to personalize it for me. I never jump over 6 ft. or so anymore and that is rare so the lowered suspension is fine for me...Anyhow...I don't think I would want to do all that "custom" work to a 03 kx250! How much HP do you guys think my kdx200 with a 88 240cc big bore kit,reed, pipe etc. will put out?

dsmitty wrote: How much HP do you guys think my kdx200 with a 88 240cc big bore kit,reed, pipe etc. will put out?

Probably more than you really need?

more than i need means it would have more hp than my modded 88 cr500 or my al baker xr600.