Maintenance & Technical > KX500 Steel Frame Conversion (SFC)
2003 KX 250 SF Conversion
mixn-gas:
Hey umberto the conversion looks like its coming along great,
im close to stating another build similar, 03 kx250 and 94 kx500,
i may be pestering you with questions as it goes,
just for clarification you just bought the normal cr500 fmf pipe? gnarly one or what? and then cut off the engine flange and welded on the kx one?
also is the 03 bike a good one to go with? i have the motor but havn't bought the bike yet, going to look at it tommorow.
thanks from logan
umberto:
--- Quote from: mixn-gas on June 28, 2015, 08:40:39 PM ---Hey umberto the conversion looks like its coming along great,
im close to stating another build similar, 03 kx250 and 94 kx500,
i may be pestering you with questions as it goes,
just for clarification you just bought the normal cr500 fmf pipe? gnarly one or what? and then cut off the engine flange and welded on the kx one?
also is the 03 bike a good one to go with? i have the motor but havn't bought the bike yet, going to look at it tommorow.
thanks from logan
--- End quote ---
The pipe I used was just a standard 89 and up FMF Gnarly. I actually used a new CR pipe, a dented used CR pipe, and the KX 500 pipe. I used the flange section of the KX pipe, and two sections from the dented pipe to lengthen the pipe 1" out where it goes towards the ignition cover, and about an inch back the other way (it was a pie shape to lay the pipe over a bit more). The CR pipe fits without the added sections, but you do have to dent it pretty severely to get around that dang coolant transfer pipe, the reed block (it kicks back in after going around the head) and to clear the ignition cover. I solved this by adding the sections to the pipe. I suppose you could use section out of the KX pipe instead of buying another CR pipe, but I already had the dented pipe.
The 03/04 is a good choice from a handling standpoint, but the 05-07 should have more room for the motor (but not handle nearly as well). You can get the newer chassis to handle if you swap out the triple clamps to change the head angle a bit. I didn't have any issues with room, except in the front where the head gets really close to the frame and restricts access for the radiator cross over hose. You will have to grind the weld on the frame and relocate the bottom radiator mount. Other than that and the tank reshaping, it's been a pretty easy swap.
I have to thank zz3gmc, he has been a lot of help. He completed an 04 conversion that is super clean. I'm pretty sure I wouldn't be this far without him.
Good luck with your conversion!
dave916:
--- Quote from: sandblaster on June 28, 2015, 01:17:17 PM ---The coil is no problem.
You might be able to use the 88 CDI but I believe the timing is different.
I think the 89 and up max out at 19 degrees at 6K rpm
The 86-88 I think max out at 15 degrees
Someone hopefully can confirm
--- End quote ---
88 is 17 degree 6k rpm/ cylmer manual, so very little differance, not sure if the wire colors vary on later kx as the pick up coil seems to change, internal pick up coil totally confuse me :roll:
Make sure u are kicking it over fast enough when trying for spark/ No plug in and kick it like u want to start it :-)
I end up pulling my hair out years ago try to get spark on a cr5/ luckly i had spare cdi coils etc or i would still be there/ turned out i was not kicking it fast enought even with plug removed {no compression} :-D
umberto:
Could I use the entire system (coil, cdi, ignition) from an 89 and up? Would I need to replace the flywheel as well? Would it fit?
dave916:
--- Quote from: umberto on June 29, 2015, 03:38:32 AM ---Could I use the entire system (coil, cdi, ignition) from an 89 and up? Would I need to replace the flywheel as well? Would it fit?
--- End quote ---
U Would need flywheel as well
pre 89 had the smaller ligher flywheel
88 on right
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version