KX500 engine in KX250 frame???

[Vortec_Cruiser]

My son told me that a KX500 engine will bolt into a KX250 frame with little or no problem. We are talking about a 1994 KX250, and, say, an E1-E14(?) KX500 engine. I'm not opposed to moderate fabrication with engine mounts, if required. Is this possible, or did someone give my son bogus information?

[desertboy]

it is possible and is not too hard as long as you have a complete engine with carb and electronics from a kx500. Thi swill require fab work to engine mounts but thats it as long as those mounts are changed it will be ok.

to do it take your bike down to frame and swigarm then look at it it is apperent then, the only addition is that i have heard on some year 250s lower frame y's need to be redone on a 99 i know it doesn't. Hope this helps

[Brad]

Dont know if your kid is right or wrong but the EASIEST thing to do is call the dealer and get the Part number for the 500 frame AND get the part number for the '94 250 frame and see if they are the same.
If not you will have to worry about exhaust mounting/clearance, radiator hoses,motor mounts and some other stuff just off the top of my head

[desertboy]

The frames are not the same, a kx250 radiator will cool and work with the 500 engine. The 500's pipe will fit into the frame with minor mods and the spark arrestor silencer will need to be extensively redone to fit, meaning the whole tube to the spark arrestor needs to be redone.

And yes the motor mounts are not the same but can easily be redone if you have some skill

[Vortec_Cruiser]

Thanks for the info. All we need now is the KX500 engine.

[CRAZY MATT]

might be easier to just buya KX 500 then try to piece one together - parts ain't cheap

( try owning a KTM)