Looking for input on stuffing a 500 into a 95 kx250 frame

[Goat]

I stumbled on a 1995 kx250 frame and some engine parts. Selling the engine parts and keeping the frame. I paid $100 for everything. No suspension, tank, seat, plastics, sub frame, or swing arm. Just a bare frame with the right radiator.

Before I get into it too far I would like every ones input that has done one of these builds. What I should and shouldn't do. Never done an engine swap like this on a bike before. A couple quads but those have more room for error. Still debating whether or not I'm using my engine or getting another one. I have extra cases and cylinder to use as the template. It's mainly going to be the winter project but I am going to tinker on it when I have time. Should be starting work in the next couple weeks so that doesn't leave much time for sleep let alone anything else. I'll get some pics of the frame in the next couple days.

So lets have it guys. What should you have done different or What did you try that worked out nice? Open for any ideas.

[ZETTNORCAL]

Goat,
               Just start putting the pieces together and it will all just come easy.  It sounds like you know how to use a wrench so it will be a breeze for you!

  I would have spent more time and I still will someday to build a better pipe for my conversion. I just put a KX500 pipe inlet welded to a CR500 pipe and then put a BIG dent in it where the water port is on the K5 cylinder. Lazy

  I just got excited and wanted to finish it so I could ride it.   So if you can try not to do that (yah right) and just take your time and build it to the best of your abilities. It will come out sweet and you  will love it and be proud to know that YOU built that SICK bike!

[Goat]

As long as I have something to ride while I'm building it I wont rush through. The excitement will still be there but I can always jump on the k5 and slow myself down and stay focused.

I do have a massively dented PC pipe to cut up and weld to whichever pipe I end up with. I don't remember where but I read that someone used the back half of the 250 pipe with the front half of the 500 pipe and it just kind of bolted on.

I'm not a great welder. Haven't had any welds break on me but they aren't pretty. When I get laid off in the fall I'm probably going to take a welding class at the local trade school. I used to stick weld like a pro but that was 12 years ago. Just got a Lincoln heavy equipment welder 2 summers ago but don't have 220 in the garage so I only played with it a couple times. It does 300 or 350 amp and weighs like 400 pounds. Hopefully moving into a house with a polebarn this summer so I can do some serious work on my truck and bikes this winter.

[junk man]

hey goat looks like its time to go shopping eBay would be a good start.
your going to need 1994-1998 250 tank,seat,plastic, triple clamps & bearings,foot pegs,shock & link,sub frame,air box & boot,cab holder,rear brake master cyl. and pedal 

I think the 500 swingarm is about 1 inch longer then a 250 so you can use a 250 sw-arm  and drill out the engine cases or use a 500 sw-arm and weld a bushing in to make the frame holes 15mm i used the bushing out of an old sw-arm strut i opened up frame holes to fit the bushings grind the with and chamfer them and install sw-arm bolt and engine without the sw-arm and tack them and get them tig welded  then you will have to make a spacer between the engine and sw-arm i used two grade 8 washers on each side this is to fill the gap from the k5 link mount

use the 250 radiators its work to make the 500 ones fit and you already have one also all new plastic UFO for about $100.00 motosports.com

good luck JM

[Goat]

Thanks for the info junk man. I wasn't sure what years were the same. Have a friends 92 K2.5 in my garage for complete rebuild and noticed the radiators mounted different but that's all I could tell from looking. I was going to use the 500 swing arm but I'm not sure now. I know a couple people that could make me some nice bushings and do whatever machining I need. Don't exactly want to bore the cases either. I'll take a look at everything and figure out what I'm doin. I have an extra k5 swing arm so that's probably what I'll use. I have 98 k2.5 forks on my k5 now so I could just swap those over if I decide to use my engine. I would like to get another engine. Can never have too many lol.

[ZETTNORCAL]

Goat,
   I have a nice swinger from that 96 I parted out, the rear brake sys., forks, triples, linkage. I will sell very cheap, if you need let me know.
   Ryan

[butchpatrick]

To start off good luck, but about the welding if it was me I would most likely if your useing stick use a 7018 1/32 rod.  I dont know if your welder is digital or nob,but if it's nob I would run it at 3 no higher because it might burn to hot.  If you can tell me how it comes out I would really like to know.  Thanks and good luck with the bike. From the steel city of INDIANA.

[cutting torch]

For the welding part, I would recommend a little 110 volt mig, and practice with it. If you know someone with a mig that is a good welder, ask them for tips, and to watch them weld. I would bet that that would be cheaper than a welding course.

Also, skip the flux core and get a bottle of gas. Solid wire with gas (C25) welds so much cleaner, and welds easier.

My current project is in two posts, and it is based off of a '92KX250. I'm sure that there are enough similarities for you to get some ideas.

http://www.kxriders.com/forums/index.php/topic,7388.0.html

http://www.kxriders.com/forums/index.php/topic,7396.msg57332.html#msg57332

Ask any questions you want. If I don't have a good answer, I'll say so.

torch

[junk man]

goat if you use the 500 sw-arm you need to use the 500 struts there about 1/2 in. longer then the 250's . its a lot of work grinding down the welds for the sw-arm bushings so if there tig welded  it would save you some work for the rest you can mig weld it  110 is what i used

you will also need rear brake pedal and master cyl.

[Goat]

Thank you all for your help. I'll have to read this a million times so I don't forget anything lol. Had some spare time today so I took my old k5 cases and cylinder and put them together and set it in the frame. Also sorta bolted my extra k5 swing arm on.

First thing I need to do is remove the front motor mounts. Then I can get the template cases in the frame better. I would like removable front mounts but not sure if that would severely weaken the frame by drilling through it.

Last time I checked the welding class was $260 but that was a few years ago. The state will also pay for me to further my education so I wouldn't pay for anything. I should have went this last winter but I was helping my dad fix up his house and building my k5.

[Goat]

Should I use the 250 or the 500 swingarm? Pros and cons of both would be great. It will mainly be my woods bike but knowing me it will see the dunes as well I like my bikes to sit up kinda high as I'm 6'3" I also like to jump anything I can so the higher the better susp. travel.

[BDI]

the best thing i can tell anyone doing this is to start with a whole bike. the reason people prt bikes out is they are worth far more in parts. so if you try to part one together it will cost you far more then buying one and selling what you dont need. as for drilling the cases goes you need to get over that. there is not one part of the bike that does not have to be modded in some way to pull this off. As for welding I would find a junk frame to practice on it, frames are super easy to blow holes in. I used a mig to weld mine so it would look factory. You better have your heat and wire speed set right, close wont cut it on this.

[don46]

Not sure the swingarm is the same between the 250 and 500, I do know the 02 250 isn't the same as the 500. I think I would keep everything the same if using a 95 250 then use 95 parts.

[Goat]

I paid $100 for the frame and almost an entire bottom end of the 250 engine. The guy was hurting for money so he was selling all kinds of stuff. I can sell the engine parts and get what I need. I'm also working a lot now so money isn't really an issue. Just trying to put money into my truck, k5 and the 250 build.

I ended up getting a subframe off ebay for $9 and a front hub for $9.50 from the same guy. Just 2 bolt holes striped on the subframe. No biggie.

I do have a spare k5 frame, subframe, and swingarm laying around. Wasn't sure if I wanted to build that into a supermoto or use the swingarm for the 250. That's why I was asking which would be better to use.

If anyone is interested in some cash to make me some bushings for the swinarm pivot bolt let me know. My friends dad sold his shop so now I don't have a place to make them.

[BDI]

I guess everyone has their own way of doing things. Some people will drive strait down the street to the store and some people will drive all the way around the neighborhood to get to the store. I guess as long as you get to the store that what really counts.