What should I do with this 99 KX 250 frame?

[Dale]

I just bought a 99 KX 250 rolling frame. My plan was to just swap the front end. After reading the above posts, Sounds like I can do a whole lot more. I have a few questions. What is the bennifit of putting a KDX 220 motor in the 99 KX 250 frame. Couldn't I just do the fork conversion and swap the rear shock and have a pretty good bike? Don't get me wrong, I love the KDX for it's low power and rock solid performance. I've had it for 6 years, It's a 98 220. When I was younger, much younger, I raced a KX125 in the NY hare scrambles. I always loved the KX. I'm open to any comments about building an awesome woods/track bike. I also have all the controls, tank, plastics, calipers etc on this rolling frame 99 KX 250. Would that carb be an upgrade for the 220 KDX? I'm sure I'll have more questions soon. Thanks in advance for any and all comments.

Dale

[scheckaet]

I'm thinking the weight, the more aggressive stance on the kx, better chassis ... are good reasons to do the hybrid. (and a bit of bling too )
KDX with KX front end is a good improvment (done it) but I'm thinking about doing a hybrid too.
I don't think you can use the kx rear shock (unless money is of no matter...) cuz they're different lenght.
Carb: send it to RB and let him work his magic, never heard of anyone swaping carbs from a kx to a kdx (probably different carbs)

[marrk_us]

Do the hybrid!!! You have 99% of what you need already and with ebecks step by step posts and a little work it'll be done. Ride your kdx til the end of riding season, take your time and make a winter project of it. Losing 25-30 lbs of worthless weight makes for an amazing kdx! Everyone should do at least one hybrid, Kawasaki couldn't keep them in stock if they made them.

[SVandal]

I imagine the suspension would be a good upgrade, but I agree with the idea of loosing 30 lbs. I did a cr hybrid and it is a world of difference (though I had a 94 kdx that I started with.

It took about 3 months from start to finish to do my hybrid and I didn't have all of the parts on hand at the start. Look at ebecks how to sticky's and then get what you will need lined out. If you started on the frame mounts, got what ever parts you would need and got the kx frame prepped you would probably be able to do it in a month of Saturdays.

When the KX frame is ready for new mounts, pull the kdx motor, swap it over, get the mounts welded in, and start bolting it together. I would recommend that you get a kx book for all of the torque specs, rebuild the suspension ahead of time, buy a pipe that will fit (some are almost a bolt in), and get everything else ready to go.

Mine only took 3 months because I bought it one part at a time and had to wait for items that I could use to pop up on e_bay at the right price, and had to mod the exhaust pipe. But the pipe is my fault for using an older style pipe on the cr frame. Its a good project that is worth the time. Good luck

[KarlP]

If you can find a good KDX motor, or even a whole KDX so that you can steal it's motor and electronics and other parts you can take your time over it and not disturb your current ride.

I had a '99 CR250 roller and bought a trashed KDX from the local motorcycle shop for $98.00

The MX frame with a little suspension work and a KDX motor is one heck of a bike. I've swapped with riding buddies on KTM's and GasGas'es and my ride is every bit as good.

I'd sit on that KX frame. A KDX motor will show up.

[Dale]

I did the fork swap last night. Went to the local machine shop that builds my motors and he let me use his press for the stems. ( bought him two 18 packs of beer for letting me use it ) The KDX was really in there! Used a chisel and Knurled the base of the stem in about 20 places. Pressed it in tight as it came out. The whole job took about 2 hours. Took it for a short ride on my track and like what I see. To keep the forks from hitting the tank I welded a flat piece of steel under the stops on the frame head. Works great, but I can grind a tad more off to get a tighter turn without hitting the tank. I used a stainless steel hose clamp to take up the space on the top of the shaft. Simply cut the screw portion off and fit it to size and tapped it into place. Nice and tight! I'll take it on a hare scramble track this week end and see how it does. Thanks for all the advice. I think I will start on the KX frame and build a hybrid this winter. I'll let you know how it goes.

Dale

[SVandal]

I did the fork swap last night. Went to the local machine shop that builds my motors and he let me use his press for the stems. ( bought him two 18 packs of beer for letting me use it ) The KDX was really in there! Used a chisel and Knurled the base of the stem in about 20 places. Pressed it in tight as it came out. The whole job took about 2 hours. Took it for a short ride on my track and like what I see. To keep the forks from hitting the tank I welded a flat piece of steel under the stops on the frame head. Works great, but I can grind a tad more off to get a tighter turn without hitting the tank. I used a stainless steel hose clamp to take up the space on the top of the shaft. Simply cut the screw portion off and fit it to size and tapped it into place. Nice and tight! I'll take it on a hare scramble track this week end and see how it does. Thanks for all the advice. I think I will start on the KX frame and build a hybrid this winter. I'll let you know how it goes.

Dale

Sounds like it works. Looking forward to seeing how well it works. For comparison, did the forks change the weight of the bike much? Curious to see what effect it would have.