125 Motocross

[GhostRider]

I know this a site for kdx's but dirtrider is useless no one ever answers you.

My question is, im thinking of getting into motocross and wondering if a 125 would be the way to go. Or would a 250 be a better way.

How does the power stack up between my kdx and a 125?

Thanks

[radonc73]

I would recommend a 250 for the power, you can always turn the throttle less. A 125 seems to fall flat on hills or in deep sand. They will also require more maint. b/c you will always be screaming a 125. So a better chance of blowing and a top end job alot more often. I am a bigger guy so it might not be as bad if you are smaller but a 250 will get you out of trouble easier if you are in too high of a gear.

A 125 will come on alot quicker than a KDX when it hits. It will make jumping alot easier. THe suspension will have more adjustment with compression and rebound and the springs should be much stiffer to take jumps with.

[KarlP]

I've had a 125 for a while, recently got rid of it, and need to change my signature.
The 125 was real fun. There is no comparing the kdx motor to the 125 motor, except that they both burn gas and make a little smoke.
A 250 is a serious machine for a beginner MX rider, if that be the case.

I'm 43 and 170 lb. If I wanted to spend some time in the MX world again, I'd do it on a 125 for the first year or two. A 125 rider with good technique and some agression is a sight to behold, zipping past those 4T.

[fuzzy]

Are you comparing 125 to 250F or 250 2-T? Stick w/ the 2-stroke regardless. After your fast ont he 125, and have done a couple of dirt cheap top-ends then sell it and get a 250 2T

[GhostRider]

So a 125 would have as much power then, correct?

Im only 65kg so a 125 would pull me nicely right?

How often on 125's do the piston an rings need doing?

And does anyone know how long one will last on tank of gas?

[2001kdx]

I just did this - I went to an RM250 purely because I ride a 50/50 mix of wodds and MX. I reccomend the 250 because it has the potential to be even a better woods bike than the KDX - this is on more open trails only though, it's a chore moving this bike through tight stuff. I have yet to got to the track with it though, I might be going on 9/8.

[Jeb]

I agree with KarlP about the 125 vs. the 250 - "serious" describes that class of bikes quite well . . .

a 125 WILL require more servicing, especially if you run it hard. If you ride frequently plan on at least 2 top ends per year (at least if you don't want to run a much higher risk of blowing the engine and want to maintain performance).

Another consideration is that you could get a 125 for mxing, ride it for a while, then modify it to a 144cc bike.

[thebleakness]

Get a 450.












:D


125s are fun, lots of fun but you really have to "ride" them. It's not going to be like a KDX where you can lug it around all day and still move. I ride with acouple people who ride 125s in the woods and they work well with some practice.

A 125 will pull you along easily at your weight. I weigh the same as you....I just decided that I need more POWA! You never mentioned, how tall are you? I think you could go for a 250 2t and be even happier, easier to ride and at least for me, more fun to ride.

[2001kdx]

"250 2t "

I agree 100%. But what the heck is 2t? 2 two? That don't make any sense!

[thebleakness]

Does it make any more sense than a 250F? Should be start calling them 250FS' and 250TS'?

[2001kdx]

250F = 250 four-stroke
250T = 250 two-stroke
250 2t = WTH?

[Jeb]

250F = 250 four-stroke
250T = 250 two-stroke
250 2t = WTH?

AHA!! There's the answer . . .

t = WTH?/250 - 2

BRILLIANT!!

[2001kdx]

This is blasphemy! the '2' IS the 'T'!!!

They don't belong together.

[thebleakness]

I could list off many other things that "don't belong together" but I don't think it would be appreciated. Leave it be!

Quit fooling around on the internet and change your jetting on that RM! Finicky those things are...

[Ondatrail]

I ride a 50/50 mix of wodds and MX.

50/50? I think more like 90 woods and 10 mx

[2001kdx]

Haven't even pulled the carb yet actually - I'm gonna this weekend so I can run 50:1 amsoil (was jetted for 32:1) Things got a powerjet & TPS, I'm looking forward to it

If someone more knowledgeable than me could answer a couple questions...

I want one size richer main & pilot to go to 50:1 from 32, correct?

This bike has a 38mm PWK - Would the KDX jets wok in there?

[2001kdx]

I ride a 50/50 mix of wodds and MX.

50/50? I think more like 90 woods and 10 mx

Hey I try to get to the track, but I wanna go more now cuz i goota scotter more suited for that event. September 8th practice, here we come!

[grump99]

Haven't even pulled the carb yet actually - I'm gonna this weekend so I can run 50:1 amsoil (was jetted for 32:1) Things got a powerjet & TPS, I'm looking forward to it

If someone more knowledgeable than me could answer a couple questions...

I want one size richer main & pilot to go to 50:1 from 32, correct?

This bike has a 38mm PWK - Would the KDX jets wok in there?

I believe you would go leaner with the above change. How much I'm not sure.

[fuzzy]

I've seen that abbreveation used for years, so I use it. I'm not really sure what it's abbrevieating either. I think it comes from over the pond.

Also, remember Mobil 1 MX2T? It's quite common.


2001:

Stick w/ 40:1

Yes, PWK jets are PWK jets however you'll probably be needing sizes that would never feasabely be used in the KDX.

Less oil=more fuel so you'll be actually richening your mixture

Have fun w/ that powerjet. Does the TPS sensor adjust it? Is there a servo on it? That would be cool...Otherwise those thing are a PITA, and only really necessary in the desert, or HUGE pro-style MX tracks.

[GhostRider]

How long will a 125 last on tank of gas as I am still planning on doing some trail riding. Thanks