My custom 400ex/cr250 hybrid drag quad

[JOHNDOE83]

I switched to a standard length 450r swingarm with a stock 450r axle, a stock 450r swingarm with a stock 450r left spacer and a right 400ex spacer for the pivot bolt to motor, lines up the sprokets perfectly with NO mods!

Everything except for the shocks, rear strut, seat and rims/tires, pipe and motor mounts is oem honda parts. Even the spacers used for the custom mounts are honda made but trimmed for fitment, the motor bolts are also 400ex honda bolts.

This conversion needs NO frame mods at all.

This would make a awesome MX atv, as it sits I can almost lift the whole thing off the ground myself. If it had mx suspension and 400ex plastic it would RIP off road.



http://i953.photobucket.com/albums/ae15/johndoe83_2010/IMG_20130126_180341.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00199.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00197.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/IMG_20130126_180549.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00201.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00203.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00204.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00202.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00200.jpg

[JOHNDOE83]

heres some of the motor mount pics, the only one I didnt get a pic of was the mount for the top, not sure if it even needs that one but im going to use it anyway for safety issues. The mount is already made I just have to weld some wings on it for support.

This front mount is supported by the stock 400ex front mount location, the spacers are made from the top motor mount from a 400ex and the bolt is also the top mount bolt for a 400ex. If you look closely you will see the only frame mod I had to do was cut the stock 400ex front mount nuts that are welded on, the vibration rattled the welds loose on the nuts, I recommend cutting them off and using reg nuts.


front mount
http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00213_zpsbe2cef79.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00214_zps43bcdbe4.jpg



bottom mounts, I also used a 400ex top mount bolt for this.

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00215_zps472168fb.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00216_zpsb1b7b2d7.jpg


swingarm spacers, this is a 450r swingarm, the left spacer is a 450r, the right is a 400ex. inside the case between the 2 spacers, is a 400ex right side spacer cut down to fit inside so there is no slop in the swinger bolt. "cr250 bolt is fatter" A 450r swingarm with these mods and a 400ex front sproket, the sprokets line up like factory.

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00217_zps8104b473.jpg

The hardest part is fabbing everything up in such a way that it all fits and works after its installed, everytime you move something you have to make sure the pipe still fits, the radiator willl work, the spark plug isnt hitting...etc...

[JOHNDOE83]

The best part is at any time I could slap on some plastics and some shocks, pegs, nerfs and this is one BAD *** LIGHT WEIGHT MX/off road quad.

Im possibly planning on building a cr80r/400ex hybrid with good shocks and some weight mods for MX racing, that I may build for re-sale value.

[JOHNDOE83]

well heres a basic parts list to use as a basic research guideline for pricing.

This is without motor, I bought a complete bike for $600. Even if you bought a higher quality bike for $1000 you will still be ahead of the game.

Most of this stuff you already have 1 set of if you have a 400ex and cr250.

around $50 in steel from lowes and home depot.

2 sets of 400ex motor mounts and bolts.

2- cr250 kickstart knuckles.

2 sets of 400ex swingarm spacer/bushings.

some type of radiator, mine was $40 and it went to a late 80s cr80r. I also have a cr125 radiator thats a lil bigger im gonna use in a future build, you might be able to make the cr250 rad work.

around $50 in misc bolts, spacers, washers "maybe".

you will need to custom fab a pipe, I recommend using a 250r pipe because it already almost fits a 400ex frame exact. to make mine fit I used the cr250 pipe flange that inserts into the motor and cut the FTZ pipe at the right angle to work for my build.

You could find a new pipe for $200 or buy used for less money.

Long story short, I routed my pipe differently then the 250r, this made the stock cr250 rad not fit which to me didnt matter . I was using smaller and lighter anyway for drag racing purposes. This is also why in my pics the pipe sits LOW in the back instead of up high. If I routed it the correct way and wasnt using such a fat pipe, it would have routed normally.

You need the extra swinger spacer, you trim it down to fit inside the cr250 crankcase because the cr250 swinger bolt is slightly bigger, a machine shop turned mine for $40, I then cut it to 3.5in and it fits perfect in the cr250 motor.

After the swinger spacer is done you can fab mounts, start at the front then top then bottom. I bought? I believe it was 3/16 flat plate steel, 3/16- 1in flat bar, 1in square tubing, 1x1 angle metal.

I custom fabbed everything and test fit 100 times, marked everything for exact fits with line marks etc... then took it to a welder.

There is also a RM250 hybrid in here that built his the same time i built mine, you should look up his thread.

Heres links to my before "mock up build" and my after "revised" build. I decided not to go into detail about the revised mods but will gladly share them if you are going into this build.

I will also get you detailed pics of the mounts this weekend.


this is the "Before" mockup build. http://www.exriders.com/vbb/showthread.php?s=&threadid=477981&highlight=hybrid

[blacknblue#2]

When setting this up as a trail do you think you could get by running a 250r exhaust or have to build an exhaust. A Good friend of mine has a 400ex frame and would be easy to talk him out of it if I told him I was wanting to put a cr250 in it

[JOHNDOE83]

Yes I would reccommend a 250r pipe, the pipe I have is a 250r based pipe that I routed differently then its normal install. Thats the only reason why the silencer isnt in the right spot and the expansion chamber sits up higher.

I was avoiding welding costs, instead of fabbing a extension piece that needed welding and a metal fabricator, I went with different routing and one single weld joint at the insertable pipe flange.

I wasnt able to make the cr250 pipe work, maybe someone else will have better luck. It might fit now that I removed some frame pieces, when I was first building this I wanted everything to fit without any frame mods.