KX Riders
Maintenance & Technical => KX500 Steel Frame Conversion (SFC) => Topic started by: junk man on March 19, 2010, 07:29:12 PM
-
I started with a 97 kx500 owned it from new had to pull the engine to replace crank seals and was just going to go over it. then i found a 2000 kx250 frame on e:bay got i for a buck + shipping so I'm going to use as many parts off the 500 that i can i bought sub frame,air box,triple clamps 250,rear brake master cylinder,01 shock,reed cage,kx250 pipe, tank & seat off e:bay I'm trying to keep it a low cost build about $500 for these parts.
I had to bush the frame for the 500 swingarm bolt then for the 500 radiators move top radiator mounts and fab up the bottom center ones and just got the frame back today from the powder coating guy I'll send comment and photos as it go's together
-
oooh,
That's Purdy! What color is that J-Man? Gunmetal Grey?
Tuck\o/
-
Mr tuck its gloss black i was thinking silver like the later kx's are but wanted to do something not so common also need to finish up the head mount thanks j-man
-
Soory JM...
I'm getting OOld. That looked like a gun metal or charcoal... Maybe I better check my meds...or , glasses..
or..
Anyway that looks great on the bench,
Tuck\o/
-
Nice!
Does the exhaust fit under the the Y without frame mods?
-
hey tuck your eye's are just fine it was a bad photo an thanks for asking.
dubious01 yes the exhaust fits no mod's for pipe clearance out of the exhaust port.
on 2 stroke frames click search for steel frame engine fitment 03/04 has good info
thanks j m
http://www.kxriders.com/forums/index.php/topic,5557.0.html
-
im wondering whether the 250 pipe might strangle the motor as the cone shape and length are designed for a 2 and half?
-
Nice!
Does the exhaust fit under the the Y without frame mods?
The Y doesnt have to be modded with the steel frames, pipe clears.
-
A lot of you have bin using cr500 pipes ? I'm not sure. I'm trying to do it cheep. I think its going to work half the pipe is kx500 fmf fatty the top part is pro circuit 94 kx250 pipe e:bay $30.00 shipped I removed 3 to 4 inch. from the 500 chamber and the 250 chamber is bigger at the tail than the 500 pipe. I think the hybrid chamber is as big or a little bigger than the stock pipe and the stinger is 1 1/4 inch. so what do you think ? on the y thing no frame mod's on steel 2 stroke frames
Today got some more work done polished the swingarm and installed it and installed the forks also found a small problem the throttle cable hits the gas thank should i use a 250 cable thanks JM
-
if youve got some of the 500 header in there and you think the sizes are somewhere near then it cant hurt to try.i thought it was a stock 250 header.
-
if you take look at the photo right below the emblem is were they are seemed the bottom 1/2 is all fmf 500 fatty and both pipes were well used I'm going to hope for the best
-
Its startin to look nice, good work fella. :-D
-
If you guys see something that in question let me know. I appreciate the help
thanks JM
-
have you got the steel bend in your throttle cable above the carb? just wondering if adding/subtracting it will help clear tank?
-
Near the lower middle left of page 64 is the 100 degree tube for keihin and mikuni carb tops.
I don't know how to "pick" page out of catalogue and post. it is a large file.
http://www.sudco.com/Carburetor/SudcoKeihinCatalog.pdf
Tuck\o/
-
I like your head stay :-D
-
How are you using the stock 500 swingarm, isn't the frame mounting for the linkage off?
-
I reread your first post, bushing the swingarm to fit the bolt, not sure I'd do that, most drill out the rear motor to 17mm and use the 250 swingarm pivot bolt. While it would be easy to build bushings for the swingarm, I don't think it would be so easy to bush out the frame, not to say it can't be done, just seems like more work than its worth.
-
nice job! what is the white box sitting on the front where your number plate would be?
-
what is the white box sitting on the front where your number plate would be?
That's an extra gas tank. I used to have one on a KX80 when I was a young boy so my friends and I did'nt have to come home for fuel. Because if we did our parents would make us come in and eat, stop riding for the day.
-
Cool! so what capacity is it and are they still available now? I was gonna make a cradle and strap a couple of 2ltr coke bottles in but that looks safer.
-
Is this the Acerbis tank that you are using?
http://www.justgastanks.com/store/index.php?main_page=product_info&cPath=360_362&products_id=350&zenid=buc64ho21n9jfshcmliavadli6
-
from looking at photos of different year kx's it looked like up to 1995 kaw used the same type swingarm as the 500 I used the stock 250 link that was with the frame and used the 500 struts there about 1/2 in. longer than the 250's it all lined up and i think the ride height is ok. (I am wrong on the years i think 93 was the last year but it looks like they kept using the older chain guide)
When i found out the swingarm bolt was to small for the frame i knocked out the bushings out of an old strut fitted and welded them on both inside and out on the outside i used a flat stone to smooth it out with them welded and sandwiched i hope they stay in place.
it was a lot of work
The gas tank is .8 gal. they don't just bolt on the clamps are for 1970's forks you have to tweak then a bit and longer hose clamps. the way they work they siphon and fill through your gas cap the transfer hose from the acerbis cap leeks i drilled it out and put an old valve stem from a tube in it also there's a brake hose issue i cut off the number plate mount and relocated the brake hose guide and put a pice of split loom over top part of hose Thanks JM
-
Today got some more work done polished the swingarm and installed it and installed the forks also found a small problem the throttle cable hits the gas thank should i use a 250 cable thanks JM
I ran in to the same problem on my 01 steely 500, MY solution (IIRC) was an aluminum throttle tube for a kx500 - grinded down to the shape of a 250 throttle tube, in a 01 KX250 housing, a 500 cable, and then I leaned the carb over just a hair. no issues since.
ALSO - I don't recommend the 100* throttle tube spacer dealio from sudco. I picked one up, and could not make it work as the cable was just not long enough.
**NOTE** not sure if it is because of my frankenstein throttle assembly, but I have 2 return springs in the carb as it stuck wide open on me at the track 1 day. First and last time my carb stuck wide open (on a brand new carb!) I decided, for peace of mind, to add the extra spring. No issues since, and I like a slightly heavier pull.
-
PS - bike is looking great. I went with the black also, but I also coated the swingarm, tripples, subframe etc.
(http://c4.ac-images.myspacecdn.com/images02/107/l_dc5e16af3d774d758c9bf0e99a59f14b.jpg)
Stoked we have a steel frame conversion page now, I haven't been on here in a while.
-
That is a very nice looking bike KXer! I want one.
-
That is a very nice looking bike KXer! I want one.
Thanks man, I love my bike. Next mod is to get that compression release. Its a PITA to kick with the IMS pegs, I think it has dented the top of my foot LoL.
-
hey KXer thanks for the info & nice ride
I called studco two times they said on the 90's out of stock 45's had one $9.00 but there's a $24.00 min. so took a look at my 1998 kx125 lots of room on it so i swap the throttle/cable/carb lid with the 500 works sweet
also bought a G force 3 reeds assembly for 500 had the guy send a smaller stuffer #130 looks like it will line up with the 250 holder,I'm waiting on some parts be for i can get it together but i hung some plastic on it to get a look
Hey KXer can we see a pic of other side also what size tank is that and how's it fit
-
hey KXer thanks for the info & nice ride
I called studco two times they said on the 90's out of stock 45's had one $9.00 but there's a $24.00 min. so took a look at my 1998 kx125 lots of room on it so i swap the throttle/cable/carb lid with the 500 works sweet
- Right on. Take a pic and post it up. There is definitely more then one way to skin a CR500, I mean a cat (lol)
Hey KXer can we see a pic of other side also what size tank is that and how's it fit
Post more pictures of my bike, I don't have a problem with that haha.
(http://c4.ac-images.myspacecdn.com/images02/109/l_3fb0ee798b6d47a0b205188a0926baeb.jpg)
The tank is a HEAVILY MODDED IMS 3.1 (I think). After trying to heat, and beat the bottom of the tank in I basically ended up cutting most of it out to fit around the head and shorty plug, and then fiberglassed the bottom (I think its like 3 layers of fiberglass) but it holds fuel now. Then I had throttle cable rubbing issues, and made a 3/8" spacer for the desert tank to sit on (with velcro on the spacer to be able to remove and go back to the stock tank ~ once I fix the stripped nut in it)
Here is my build link on the site to (by the way) http://www.kxriders.com/forums/index.php/topic,4978.0.html (http://www.kxriders.com/forums/index.php/topic,4978.0.html)
-
also bought a G force 3 reeds assembly for 500 had the guy send a smaller stuffer #130 looks like it will line up with the 250 holder,I'm waiting on some parts be for i can get it together but i hung some plastic on it to get a look
What do you mean by smaller stuffer?
On my conversion I had the 01 250 that wasn't enough power and bought the 500 powerplant (which 2 rides later HAD to be shipped to Stewart) so you and I did the conversion from different directions.
But with mine, I used the airbox from my 250 frame (01), and then when I got the V force reeds from Stewart, it bolted right up to the PWK. Don't get me wrong, it takes some "Encouragement", but just do it on a warm/ hot day with the bike in the sun for a couple hours so the rubber parts, (READ boot/ intake) get soft and it'll all go together.
If I read it right, you went with a 250 reed cage and the 2000 250's air box?
-
just an update bolted on the radiators and found the fork leg hits the cap so I'm working on that also making brackets for the shrouds and some small things to due maybe next weekend i can take her out :-D
-
:-D its done something i wanted to do for 10 years after seeing a kit in a dirt bike mag. first time out no problems what to speak of bike handles good still need to dial in the shock and jetting. I put a larger needle(N82N and it seems a little lean 1/4 to 3/4 throttle on a good pull so I'm going to put the stock(N82M) one back in i think 168 main 60 slow jet is in now. In the stock frame i had the timing advanced all the way and advanced the exhaust valve timing it came on quick now i have the timing and exhaust valve set stock and with the pipe i made and a Vforce 3 with the smaller stuffer it has tons of torque
thanks to this web sight and all the members :-)
thanks JM
-
Your bike looks really nice! It looks like it came from the factory like that. I gotta get off my ass and get mine done!
-
Hawaiian thanks! it took me a long time four mounts. I was going to use 94-98 body on my 2000 frame i cut off the rear shroud and top sub frame mounts off to fit the 98 parts but the tank wouldn't fit so i had to put back all the mounts
hey man hope this gets you motivated and keep on wrenching JM
-
That does look factory. Good job. I think I need to stay out of this section :p You guys are making me want to build one.
-
AWSOME!! Looks good!
Goat, Just do it, start getting parts, you allready got an engine!
-
I think Im going to my friends house to get the welding done. Thats the only thing holding me up right now. Ive got a 5 week break in races, been racing enduros every weekend since march, so hopefully I can get the majority of it done.
-
Hey good luck and hook us up some pic's
I used a lot of the 500 parts one of these parts is radiators they can be used but will add a lot of labor,its better to use 250's
Rode today, its getting hot and dry out in the Mojave desert. the stock jetting worked good.After riding the 125 the 500 is stiff i have all the adjustments out 15 and 16 clicks I'm thinking about putting back stock fork springs and using a 250 shock spring
-
AWSOME!! Looks good!
Goat, Just do it, start getting parts, you allready got an engine!
Got me a frame for dirt cheap :D Started my own thread so lets hear your ideas.
http://www.kxriders.com/forums/index.php/topic,7482.0.html
-
update the rear shock i used i got off eBay the guy said it was in good condition well it was beat. the guy gave me a refund and let me keep it.
Well i put a seal and new oil and gave it a try, hard to adjust and it still leaked.
two weeks ago i pulled the shaft assembly out of my 500 shock and disassembled the 250 shock.
the 250 and 500 bodes have the same bore size and the shaft assembles are the same length,so i installed the 500 shaft assembly in a 2001 250 body.
the 500 shock was re valved by Scotts performance products so I"m happy to be able to use it. road it up and down my dirt road i think with some fine tuning it will be right on
for all you guys building these things keep up the good work JM
-
Very nice!
I like the way the 2000 KX250's handle so with the extra grunt I'm sure it is a blast to ride.
Thanks for the write up!