KDX vs 125mx... advice?

[speedy1]

I'm not too worried on the top end as the bike (although older) does not look all that used. I weak top end might not be bad for smoother power delivery as long as it doesn't cause mechanical issues (piston skirt breakage, etc) hard starting, or running issues. If I need to rebuild it, I should be able to swing it though.

As long as everything starts off in good working order, I'm usually pretty good at keeping things that way. I'm pretty meticulous about maintenance and will probably tear the bike down somewhat this fall and clean, lube and reassemble anything that looks suspect. Of course, I will replace anything that might make the bike unsafe first off.

I guess we'll see :)

 

[speedy1]

new ride :)

I ended up picking up the 92... (correction) 91 KX 250 for $750. The bike is actually in pretty good shape. It needs tires and a few odds and ends, but it runs well and looks well cared for. Not sure if I will add the flywheel weight or no. It doesn't seem quite as angry as the 1996 CR I had.

I may change the gearing downward to make trail speeds easier to attain in the right rpm range, but I think it's going to work ok for me. I plan to tear off what's left of the white number plate backings and shine er up for a cleaner look. Should be pretty decent when I get done (I hope).

Here are a couple pictures... correction. one... very small... low resolution picture. wow... 100kb attachment maximum. That's pretty terrible.

Someone mentioned being able to download a service manual for $10 or so somewhere, can anyone help me find this? The shock needs seals and oil and I don't want to attempt this without a manual for guidance. Thanks again for all the advice, even though I kind of went my own way :)

 

[Joburble]

For trail riding I think a 250 is a better choice than a 125. Time will tell if you need a flywheel weight or if the gas tank is big enough. Have fun on your new bike, and if it's too harsh for gnarly tight uphills with no run up I am sure you can mod it somehow to suit, go and enjoy!

UNFORTUNATELY however, you will now have to ask your KX questions in the 2-Stroke Discussion forum :fft:

 

[speedy1]

wow... being escorted to the door already. never been kicked out of anything before... kind of hurts.

 

[speedy1]

how about if I draw a little D inbetween the K and X on the shrouds? :)

 

[Joburble]

You will probably find the same people answering KX questions in the 2-Stroke Discussion forum plus a plenty experts on the KX. It's not the door your being showed to, it's just another room.

 

[julien_d]

You'll like the 250 in the woods. Just be careful with that whiskey throttle, as if you grab a handful of throttle on a 250 in a bad spot you're gonna know it QUICK. I spent a lot of time on an 89 yz250 in the woods, and it was great fun, but would scare the crap out of me once in a while. A flywheel weight would be a great idea.

 

[WoodsRider]

Before spending $ on a FWW, check out the "Torque Spacer" from Moose. Basically it goes between the reed block and case, lowering the crankcase compression (not cylinder compression) making low-end power more manageable in the woods. Dialing the jetting in for woods riding also makes a huge difference.

I wouldn't spend much time on cosmetics. Your first couple crashes will take care of that.

 

[speedy1]

torque spacer...

I have read a little on this since you posted. Does this just shift the power into the low to mid revs, or does it increase it in the midrange? I wouldn't mind a shift, but I don't need an increase in the mirage as it seems this would make the hit more intense.

If it does what a flywheel weight would do for $30... I'm in. Please let me know. Thanks for the input.

 

[julien_d]

It shifts the power lower. Sort of like having a longer header before the expansion chamber.

Nothing close to what a flywheel weight does, but perhaps helpful in a different way.