kranker1450's 2000 kx250/k5 conversion

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kranker1450
kay i am going to pick up the 2000 KX250 donor bike this weekend for the k5 conversion. I am looking at a early 90's k5. It is all there but rough. Runs but will need a rebuild. What would be a reasonable price for the K5. I am sure I will have alot more questions as i go but so please bare with me. i have been reading alot on here. can you get the pipe from service honda or direct from FMF?

Thanks everyone.

I will get some pics of the donor bike after i pick it up.

motopunk

... better you buy a cr500 pipe from fmf or pro circuit and modify it a little bit for the kx... thats the only diference what the service-kawasaki-pipe is. the pipes are exlusive made by fmf, only for service-kawasaki. and its very hard to get one of this expensive exhausts. i´ve tried it at the european importeur for service-kawasaki . 380,- € only for the pipe...not in stock and i should wait 3 months!?! undecided

so i bought a cheap used cr500 pipe and new pro-circuit-304-silencer, cut off the big exhaust-bushing off an old 250-pipe and after little mashining and welding ... voila... runs and sound great. my costs for complete exhaust € 200,- smiley

and in the end my coversion looks like an oem-bike . wink

kranker1450

Thanks Moto for the info! Any year honda pipe i should look for? I will head that route.

motopunk

any cr500 pipe ´1989-2001 will work ... smiley

kranker1450

Thanks again Moto! From what i have been reading sounds like the cr silencer also. When modifing the pipe do you just need to change out the end that goes into the cylinder for the kx one? Plus alittle pushing and pulling i would expect.

Thanks again

motopunk

yes... complete honda-exhaust with all needed mods to fit...

here you can see my ´93-coversion some steps you could do also on your bike... http://der-motopunk.de.tl/projekt-kx500-.htm

kranker1450

Awesome , Thanks Moto for the link!

[Sandblaster]

Okay so a little back ground first. i stopped racing motocross 20 years ago. At that time i was racing a 93 KX500. My wife at the time didnt like the risk and we just bought a house and were starting a family so racing and the K5 went. 20 Yrs later i am divorced and the kids are doing well so i thought it was time i started riding again. Dont want a 4 stroke so i bought a 2001 kKX250 gave it some love and have been riding it since May. Man have i missed riding dirt bikes. I really wished i wouldnt have waited 20 yrs to start back up. Here is the 01 KX250 i have been riding.

2000 kx250 TO k5 conversion 1.jpg (102.92 KiB) Viewed 5666 times

It has been really fun to ride and i have been having a blast but, I really miss the bark of the K5. So i found this place and thought i would try to do my own conversion. I really like the 99-2001 KX250 chassis. So i figured that is the chassis i would use plus then i would have 2 of the same yr chassis so they would share all of the parts minus motors.

Here is the donor bike i just bought this saturday. i picked it up for $500 it is a 2000 KX250 that has a blown motor but everything else is there and in pretty good shape.

2000 kx250 TO k5 conversion 2.jpg (80.49 KiB) Viewed 5666 times

Now all i need is the K5. lol

Thanks for all of the info.

[Sandblaster]

Picked up a 1990 K5. It is suppose to have a fresh topend with about 5 hours on it. It runs pretty well needs some carb work and jetting. Has plenty of compression. Rest of it is pretty rough. I think it was one of those where he just did what he had to to keep it running not much else. I am going to need a new carb intake boot. I have read that the KDX one works better for the conversion. Is there a paticular year that works best. Or what about a boyseen rad valve for the 500. I paln on using the 2000 KX250 airbox. Over all I am happy with the purchase though and I think it will make a good donor. Plus i will give it much love. It just feel better to have a K5 again. cool

Thanks for looking and the help.

2000 kx250 TO k5 conversion 3.jpg (156.39 KiB) Viewed 5666 times

[Sandblaster]

Well I got a little farther on the build or i guess tear down at this point. I got the the donor frame all disassembled at this point.I need to power was everything to get it cleaned up.Sorry about the blurry pics all i have is my phone.

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I got the motor out of the donor k5. Looked into the exhaust port and it looked real nice in there. Still has the cross hatch on the cylinder walls. Looks pretty fresh. Here is a pic of the K5 next to the kx250 motor.

2000 kx250 TO k5 conversion 5.jpg (85.38 KiB) Viewed 5666 times

Know I need to get a 43/64 drill bit.

what is the best way of cleaning the motor with out tearing it apart?

[Sandblaster]

Just a little update. I have been gathering part for the conversion. I have not been able to work on the conversion due to the winter and the cold. My shop does not have heat in it so I haven't been able to work on it. I have not given up on it. Just need some warm weather.

Foxx4Beaver
that's what dining room tables are for!....I've assembled a few motors on my coffee table while watching tv.

kranker1450
LOL. fortunately the motor is together. I need to do the welding and fabricating of the mounts and the exhaust. My welder is a little heavy to be taken into the house. lol

I have been spending the downtime collecting parts for it. I have almost everything I need/want. I have bought some things from fellow members one of which was Sandblaster and would just like to say he is a great guy and would highly recommend purchasing parts from him.

The plan is to get everything made and fitted and then assemble it. Ride it for a few weeks a month and the tear it down and powder coat everything after no more welding and grinding is needed. assemble with mostly stock stuff and save the goodies for after the frame gets powdercoated.

Thanks Tom

[Sandblaster]

ok, so I have not been able to do any work to the K5 due to the weather still. I thought I would atleast post a pic of some of the parts I have been gathering for it. Enjoy!!

2000 kx250 TO k5 conversion 6.jpg (93.87 KiB) Viewed 5666 times

[Sandblaster]

I have a couple questions on the 99-02 conversions. First, when fitting the crossover hose from the radiator to radiator I know you grind down the pinch weld to gain room. I was wondering if anyone wished they would have notched the frame slightly to gain more room? Here is a pic of the area I am talking about. The area I am talking about is marked "smooth" in the pic.

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The next question is for anyone who has used the JFab headstay kit. When putting it on I can not figure out anyway to get this thing to line up. It is a 2000 kx250 frame with a 90 k5 motor. It looks to be way off or I am really missing something easy. Here is a pic of what I am talking about. You can see the bracket actually touches the headstay mount on the bottom. This is after flipping the bracket upside down to gain the extra room. Also the piece sitting on the bracket in the fore ground is the rest of the bracket kit that is needed to be welded on to mount to the bracket. There are 2 of these pieces. I must be really missing something. I have asked JFab to take a look at the pics to help me out. I would like to say that I am in no way bashing the quality or workmanship of this kit. I am missing something and just put this out here for help nothing more. I think this is a quality kit and I am very happy with the purchase.

2000 kx250 TO k5 conversion 8.jpg (95.44 KiB) Viewed 5666 times

Here is a pick of the over all motor in the chassis so you can get an idea of how it is setting. It is bolted through the swing arm and the lower mount lined right up. It has a bolt through it and the front mount has been cut off and tack welded in the current location to work with the rest of them. Thanks for looking.

2000 kx250 TO k5 conversion 9.jpg (101.44 KiB) Viewed 5666 times

[Sandblaster]

motopunk

the j-fab headstay kit is a cool thing... but you have to make your own brackets. the kx250 headstay-brackets could not used or modified to the kx500 engine. the k5 engine sits closer to the mounts in the frame.

which radiators do you want to use? the stock 250-rads would work with only cutting the tube to the right length, that goes to the cylinder on the left side .
you should contact don46 . he had made several of this 99-2002 frame conversions.. maybe he could help you a little bit forward...

kranker1450

Just spoke to JFab. He cleared everything up. Great guy. As i thought and as Motopunk said i need to make my own bracket. No biggie, just thought i was missing something else.

Moto: I am planning on using the 250 rads. They will fit with just the grinding of the pinch weld with a little clearance. Was just curious if anyone wish they would have notched the frame afterwords for more clearance. Figured now is the time instead of later.

Thanks

motopunk

how was the fitting before with the 250 engine? i do not understand the reason for grinding on the frame, because this are the rads, made for this frame..
mounting with washers to get the rads a little bit away from the frame is in my eyes a better option. 2. option : cut off the rad mounts and lift the rads up u little bit , but watch out, that the fork legs couldn´t touch them by full turn of the handlebar.


i have an 86 k5 engine in a 93 250 frame with k5 rads..because the bike is completely assembled from used ebay-parts and new spareparts. so i could do it without any modifying to the 90-93 paralell cooling system. the k5-rads did also fit perfectly to the 93 kx250 frame. all i had to do was made little brackets to get them a little bit forward on the upper side to find the clearance for the big crosstube between tank and frame.

kranker1450

moto: With the k5 motor the gap between the cylinder is greatly reduced. If the weld is not ground down I am afraid that the hose would chaff and eventually wear a hole in it. I will be moving the lower rad mount forward slightly to gain some clearance for the hose to cylinder which will push it into the weld on the front. This is why I need to remove the seem. Hope that makes sense. With the 250 motor in it there is plenty of room between the head and the frame for the hose to have ample clearance.

Thanks Tom

motopunk

ok.. now i see what your thinking is ... some times its hard only imagine some things without seeing the parts directly...

[Sandblaster]

kranker1450

2000 kx250 TO k5 conversion 9-1.jpg (91.72 KiB) Viewed 5666 times

[Sandblaster]

don46

I smoothed the area for the hose and put another piece of rubber in fact I think it was a heavy duty heat shrink in the area that rubbed to pervent wear. I too like the "works" pipe look. always used those on our race bikes as well, wd-40 after every wash and if they looke a little ratty a little naval jelly and back to the works look. I really liked the 99-02 conversion it was by far the easiest to do and the frames are plentiful. I think the only difficult part was the tank, warming and reshaping to clear everything. looks good