kdx hybrid in mx use?

[SAPPER]

hey guys i've been racin moto awhile and ride both a 125 and 250 2-stroke but i have always wondered how could i get the 250 power with the 125 handleing. well i've always wanted a kx200 or kx220, but i was wondering how well this would work and if the 200 or 220 could match the power of my 250 and the handling of my 125. we were going to buy a 04 roller for it but i decided to ask you guys before i did the project. if i did go along with the project what motor to used e series or h series and which one is better.

[Colorado Mike]

If you're asking if you can get the power of a 250 MX bike out of a KDX 200 or 220, The answer is no. Not sure why you would even go to the trouble of trying to get the 250 power into a 125 frame, the difference in weight isn't enough to screw with in my opinion. There's a reason the 250's are built a little stronger. If you just want a nice handling trail bike that can motor around an MX track too without killing you, then the hybrid is a good route to go. If you just want the fastest 125 frame on MX tracks, then you might as well put a KX500 motor in there.

[Julien D]

There was a kx250 engine in a kx125 frame a while back on TT. The guy didn't know what it was when he bought it. It was purchased as a kx250. Looked really nice, and I'm sure it was a wicked bike.

For what it's worth, no, I don't think a kdx 200/220 engine will be competitive against 250 2t mx bikes. If you could run it in the 250 class against 250f's and 125's then yeah, I think you could make a 200 hybrid that would pull it's weight in a moto.

[SAPPER]

ok so no they cant match the power of my 250. but im runnin lights class on my 125 and 250 but also runnin open with the 250 so could it match my 125 or a 250f?

[Julien D]

The power delivery is different, but not lacking really as compared to a 125 or 250f. I had no problem smoking an rmz 250 on my 200. So, with some mods, yes I think that's doable.

[SAPPER]

well i can tell you guys that the reason i dont put a 250 motor in a 125 frame is because the last guy i heard did that he broke his frame (didnt look good) so how well will it do jumping becasue i dont feel like goin to the hospital because my frame broke because the motors to heavy.

[KarlP]

The 200/220 motor in a 125 frame ought to be just fine. I can't see it breaking anything.
I don't see much, if any, advantage to a 200/220 motor going against 125's on a typical MX track. The motor is really best suited to offroad riding, but it would come down to the rider.

Why not build the hybrid just for the fun of it? The worst that could happen is you end up with a really good woods bike.

[SAPPER]

okk if i do go ahead a build the hybrid (once we get the money) i think i will but which motor would be best for it the e series or h series? and wat model frame is best to use i was think 03 - 04 and wat is the most difficult part of the project? any other tips would be helpful.

[scheckaet]

There are several builds already done with details in this section. Only one that I know of with the e serie.
Nothing really "hard", just a matter of patience.
If I do another one, I will buy a welder and give it a try. Most of my build cost was welding (frame mounts, pipe mod and silencer)
Get a roller in good condition, you'll also need a kx 250 silencer from the same year to mate with the KDX pipe since the 125 is a smaller diameter.
Couldn't find one so I had to have one custom made....$$$
If you can weld, easy project.

[SAPPER]

i heard the airbox was a real pain and wat pipe would be the least trouble? and i my dad is good at welding so were good there. and wats the difference between e sereis and h series engines?

[scheckaet]

none of the pipe I tried were a straight bolt on (expected)
The procircuit seemed to line up a bit better, but I used my FMF torque because I wanted to keep my low end torque. I had to weld an adapter to clear the frame.
Check my build if you need more info.

[SAPPER]

ok i heard the airbox is a real pain so how is tht? and wat motor is the best to use?

[Tedh98]

ok i heard the airbox is a real pain so how is tht? and wat motor is the best to use?

If you look at the other threads, you'll see how the air boxes were handled.

I went with an H series b/c it supposedly has fewer problems with the KIPS system and I wanted the most recent version of the engine for long term parts availability.

Many that have ridden bikes with both engines like the E series better.

I'd say go with whatever you can get the best deal on, I doubt that you can go wrong with either.

[SAPPER]

ok kool i got my eyes on the h sereies so ill stay with the more recent motor. thxs guys for evrythng if i get the money i will most likely go ahead with this project thxs for all your help and remember stay 2-stroke!!!

[SAPPER]

wat years are the h series and e series motors?