KDXRIDER.NET

What's better to start with? Is there much difference. The more I look into all this and the amount of $$$ I may be putting into a KDX build, I'm thinking of going the hybrid route.

You could use either, but the 125 is going to be an easier build related to the pipe. The cradle on a 250 frame is larger to accommodate the bigger engine. When the KDX engine is in the 250 frame, there is a large gap between the engine and the down tubes. You'll would need to cut the pipe and add an extension. When I mocked up a 250 frame once there was a ton of room, it looked a little funny compared to the same engine in the 125 frame.

+ the 250 is a bit heavier than the 125

Use a 125 frame.
As Ted said, the 250 frame will cause pipe fit-up problems.

125 frame is the way to go, my next one will be an 04-05 (currently building one on a 01 125). You can find 99-05 125 parts and bikes pretty cheap. The Hybrid forum has every answer you need, backed by lots of firsthand experience!

I am currently in search of a 125 frame for myself, but that may wait for another winter. My buddy is going ahead with his 250 frame build, we'll post up build pics as things progress.

Will my KDX250 motor have header pipe issues in a 125, or should I just get a KX250 frame?

For KDX200/220 hybrids use a KX125 frame.
For KDX250 hybrids use a KX250 frame.

tlevta wrote:Will my KDX250 motor have header pipe issues in a 125, or should I just get a KX250 frame?

I have done a few kdx250 conversions and I use kx250 frames because the frame mounts line up like it was made for it. I have been using header pipes that are made for the year of kx250 that the frame was from. On my first build I noticed that the kdx pipe would work bu you have to rework pipe mounts and make changes on the silencer to make it fit and mount up. If you use the pipe and silencer to match the frame it is a bolt on deal.

JTSDAD wrote:

tlevta wrote:Will my KDX250 motor have header pipe issues in a 125, or should I just get a KX250 frame?

I have done a few kdx250 conversions and I use kx250 frames because the frame mounts line up like it was made for it. I have been using header pipes that are made for the year of kx250 that the frame was from. On my first build I noticed that the kdx pipe would work bu you have to rework pipe mounts and make changes on the silencer to make it fit and mount up. If you use the pipe and silencer to match the frame it is a bolt on deal.

When you say "KDX250" conversion are you talking about a 200/220 into a KX 250 or a 250 KDX motor into a KX250? I just started a 2001 KDX 220 into a 1998 KX 250 so any info is appreciated.

OsoBlanco wrote:

JTSDAD wrote:

tlevta wrote:Will my KDX250 motor have header pipe issues in a 125, or should I just get a KX250 frame?

I have done a few kdx250 conversions and I use kx250 frames because the frame mounts line up like it was made for it. I have been using header pipes that are made for the year of kx250 that the frame was from. On my first build I noticed that the kdx pipe would work bu you have to rework pipe mounts and make changes on the silencer to make it fit and mount up. If you use the pipe and silencer to match the frame it is a bolt on deal.

When you say "KDX250" conversion are you talking about a 200/220 into a KX 250 or a KDX motor into a KX250? I just started a 2001 KDX 220 into a 1998 KX 250 so any info is appreciated.

He's talking about a kdx 250 conversion not the 200/220.