Frankenbike KX250 - do I keep it?

[mullbags]

I managed to end up with a 1997 engine in a 2000 frame instead of the 2002 complete bike that was advertised on craigslist, also learnt the important lesson of checking VIN's before buying a bike. So I have rebuilt the top and bottom end and struggling to get it to run. I am wondering if the 2000 PWK38S is a disadvantage with the 97 engine? Should I get rid of the 2000 ignition system and find a 97 ignition system? The Platinum pipe is probably a 2000 as well, it's definitely leaking pretty good at the header. Should I just cut my losses get this bike running and sell it for $1500 I've spent so far and find a 2002 or newer like I was originally looking for? To improve the brakes and suspension another will probably take another $350. I've heard a lot of good things about the 97 engine but will it actually run like a 97 engine with all the 2000 bits on it? Or do I need to dump even more money in it to get it to run properly. I ride woods in the summer, intermediate track in the winter, and trips to Moab in the spring and fall.   

[IQRaceworks]

I ran into the same problem. I picked up a nice "1998 KX250". Once I got it home it actually turned out to be a 94', with forks off of a 93'.  The more I searched around....it seems like for the most part (as far as performance goes)....there really isn't much difference between the 94-00' bikes....well not enough to make me want to sell my bike just to get another one. I figure that just about any 15-20 year old buy has a pretty good chance of having other year parts on it.

[KXDINO]

What do you mean it struggling to run, not much power , hard to start, jetting off , need more info, the leaking header is easy to fix , what ever you buy is going to need work , I think you can get this machine working good , any mod to get the brakes and suspension working better is a big step forward , as your body will appreciate the improvement , what did your rebuild consist of ? Most of the guys on this forum , including me never worry about how much it cost , if you did we wouldn't be riding bikes as we all know its a bottomless pit , treat it as a adventure and enjoy the challenge .

[mullbags]

I figured out why I'm having trouble getting it to run and it's the pesky woodruff key. Apparently I didn't tighten the flywheel down enough and made a mess of the woodruff key! And the magneto looks like it moved so that is probably a large part of it. I replaced both top and bottom end with Wiseco kits (realized it was not the year I thought I was getting when the 02 parts arrived and wouldn't fit). I did actually really enjoy rebuilding the engine.
I just read somewhere if you want a 97 engine to run like a 97 engine you need to match it with the right pipe, carb, and ignition. So should I sell the existing pipe, carb, and ignition or is it in fact going to work just fine and still get the same amount of HP. I was intending on putting money into this thing but was hoping it was for performance enhancing mods and not just to get it to run to it's stock potential. It's getting kinda hard to keep justifying the cost to my wife when the 89 KX250 I just sold ran like a champ